Welcome to our guide to help you choose the absolute Best Orbital Sander.
Nothing is more tedious than sanding large wooden surfaces by hand. It’s outright boring and a lot of work. It’s little wonder then, that in this day and age of superior electric power tools, most people use some form of electric sander. The most common and versatile being the orbital sander.
Many a novice may think that one sander is pretty much like another. Nothing can be further from the truth. Before buying your first sander, you’ll need to decide which is going to be the best for the woodworking projects that undertake. Later in the article, I’ll discuss orbital sanders and belt sanders in some detail for those who are having trouble deciding on the perfect sander for their needs.
As always, our main aim is to help you find the best products and this article is no different. So we’ll begin with a review of the best orbital sanders and then move onto all the other stuff that you may want to know about these tools.
Reviews | Best Orbital Sanders
Most orbital sanders are corded tools, though there are a few battery-powered models and you can also find pneumatic orbital sanders. Though for these tools, you’ll need an air compressor. For the purposes of this review, we’ll be focusing on the most popular offerings. These being corded (120V) orbital sanders.
We’ve done a good job of selecting options for every category of power tool buyer. At the top of pile, we’ll be looking at two Festool models. I doubt that any knowledgeable woodworker can dispute that these guys are the best in the business when it comes to specialized woodworking power tools. Though there are many who aren’t up to paying Festool prices – these orbital sanders are really for those discerning few who want the best of the best.
At the other end of the scale, we’ll be reviewing a very affordable sander from Black & Decker. To my mind, this company (now owned by DeWalt) is the king of DIY power tools. The Black & Decker orbital sander that I’ll be reviewing is cheap enough so as not to scare away the home tool user, yet still of a standard that can compare quite favorably to any of the more expensive options.
Somewhere in the middle, we have a wide selection of options from the most popular brands used by contractors and the more serious DIY tool buyer. As is to be expected, DeWalt appears in the lineup, along with their closest rivals – Makita and Bosch.
So there really is something for everyone in this review. As always, we’ve done the research, taking that burden off your shoulders. We’ve selected the best that there is. This is both in our opinion and that of tool buyers like you and I. We’ve also mixed things up, by selecting a variety of options – orbital (finishing) sanders, dual-mode, and random orbital sanders.
I’d think that, if you’re in the market for the best orbital sander, this is the place to find it.
DEWALT DWE6423K — 5″
Variable Speed Random Orbit Sander.
- 3.0 amp motor that spins the pad at 8,000 – 12,000 OPM
- Shorter height allows the user to get closer to work piece
- Separate counterweight design reduces vibration for improved comfort
- Rubber over-mold in all of the critical areas of the sander
- Improved dust-sealed switch to protect against dust ingestion for longer switch life
- Improved dust collection and one-handed locking dust bag
- Dust port is designed to fit directly to the DWV010 or DWV012 dust collectors
- To attach dust port to other vacuum systems with 1-1/4″ hoses, use DWV9000 Universal Quick Connector
As one of my favorite power tool brands, I will always give DeWalt products a rave review. So yes, I do display a degree of favoritism toward DeWalt tools. But I know I’m not alone in this opinion. There’s a good reason why so many professionals and DIY enthusiasts choose DeWalt tools over any other. It, therefore, goes without saying that I would wholly recommend the DeWalt DWE6423K to anyone looking for a top-grade random orbital sander. It’s a magnificent tool.
The 3A electric motor provides enough power to chew through relatively tough sanding work on any type of wood. With the excellent control of a variable speed trigger, the pad orbits anywhere between 8000 and 12,000 oscillations per minute (OPM). A separate counterweight and superb padding on the handles help to minimize vibrations. This is a thoughtful consideration, those super-fast vibrations that you get from an orbital sander leave your hands tingling and numb after a session of sanding. So you can work longer and with greater comfort. Along with a weight of only 2.9 LBS, this is a nimble and easy to use tool.
The compact height of 5.5” gives you a great advantage as you’re able to work close to the piece that you’re sanding. Dust collection is fully taken care of. The DeWalt kit includes a dust collection bag. You can also connect it to the DeWalt DWV010 or DWV012 dust collection systems. Alternatively, the DWV9000 universal adapter will allow you to connect the sander to any vacuum with a 1¼” hose.
You’re able to use 5” Hole Hook or Loop (H&L) sanding discs. The DeWalt has a ³⁄₃₂” orbit diameter. It also has a pad brake. Considering that these machines produce fine dust that finds its way into every nook and cranny, it’s great to see they’ve fitted this tool with a dustproof switch.
The DeWalt orbital sander comes with a carrying bag that is, like all DeWalt storage systems, a tough item. It’s clear that this comprehensive orbital sander is of the highest quality standard, is easy and comfortable to use, and very practical. You have the reassurance of a 3-year warranty, 1-year free service plan, and 30-day money back guarantee. That’s another great benefit of buying DeWalt and you can be certain that you’ll always receive the kind of service you expect from the technical guys at DeWalt.
Bosch 1250DEVS — 6″ Electric
Variable Speed, Dual-Mode, Best Random Orbital Sander.
- Powerful 6.5 Amp dual-mode, multipurpose sander
- Two sanding modes, random orbit mode for normal stock removal or fine finishing and “turbo” driven eccentric orbit mode for aggressive stock removal at five times the rate of the normal random orbit sanding mode
- Mode selector lever allows quick change between random orbit mode and aggressive turbo mode
- Soft Start reduces start-up torque
- Constant Response circuitry maintains pad speed under load
- Soft microcellular backing pad has the pliability necessary to ensure a smooth, fine finish on flat or contoured surfaces
- Integral pad dampening system provides braking of the pad spin to prevent swirl marks when removing sander from workpiece
- Rugged die-cast aluminum gear housing with exclusive dual-bearing pad mount for long-life and minimization of wobble and vibration
- Tapered soft-grip top, plus ergonomic handles for comfort and control
- Uses widely available industry-standard 6-hole 6 In. hook-&-loop discs
- Variable-speed dial to match speed to work piece and task
- Passive dust collection system requires vacuum cleaner and hose
- Dust port accepts Bosch hoses and standard equipment VAC002 hose adapter allows connection to 1-1/4 In. and 1-1/2 In. hoses
Versatility is the name of the game with this exceptional dual-mode orbital sander from Bosch. Basically, you’re getting an orbital and random orbital sander in one tool. It has a big working capacity and they provide an excellent variety of sanding and polishing discs for the 1250DEVS.
For big jobs, this Bosch model is ideal. It has a great 7.7” diameter barrel, accommodating H&L discs. With the flick of a switch you’re able to engage a “turbo” mode that provides the aggressive power of an orbital sander (270 – 600 RPM). For when you want to do finer work, it will function as a random orbital sander with 3100 – 6650 OPM. The power is derived from a mighty 6.5A motor with speed control via a variable speed dial.
The 1250DEVS makes use of 6” (H&L) pads and has an orbit diameter of ³⁄₁₆” or a radius of ³⁄₃₂”. This a relatively big orbital sander with a 12” length and 6” height. It’s also on the heavy side at 5.3 LBS. This is to be expected from a large and very powerful machine like this. You should expect a fair deal of vibration. But this is taken care of, to some extent, by the soft padded handles. It also has a removable side handle for better grip when doing heavy-duty sanding. The die-cast aluminum gear housing makes use of a dual-bearing pad mount which also helps reduce vibration and wobble. This is an incredibly durable design, that’s unique to Bosch.
Constant Response electronic circuitry maintains a constant power output. The Bosch 1250EVS won’t slow down when it encounters a stubborn knot in the wood. The soft start system also does a great job of controlling start-up torque. In addition to all these great electronic controls, it has an electric brake. The soft pads add to the perfect finish that this sander delivers. It creates a smoother, flatter finish and allows the sander to adapt to curved surfaces. For perfect fine finishing, it has an ultra-soft finishing pad which is also perfect for contoured surfaces. In line with the versatility that the Bosch 1250EVS offers, you also get a hard pad for heavy-duty, aggressive sanding on flat surfaces.
Channels in the pads assist in improved dust collection. Combined with a very efficient dust removable system, it’s one of the best for a clean, almost completely dust-free working environment. You can hook it up to any shop vacuum, an adapter makes it compatible with either 1¼” or 1½” vacuum hoses.
If you can’t decide between a regular orbital sander and a random orbital sander, the dual-mode Bosch 1250EVS gives you the best of both worlds. Along with the versatility of both modes of operation, it’s incredibly powerful with a conveniently large disc. While this size makes it faster to clean up large flat surfaces, it’s not going to be the best in tight corners and delicate, small pieces. For that, a smaller sander is the better option. All the incredible design features that have gone into this tool make it exceptional for fine ultra-smooth sanding and it will make light work of cleaning up uneven rough wood just as effectively.
Festool 571782 RO 125 FEQ — Rotex Sander
Best orbital sander on the market. Professional grade all the way. Worth the extra money, if you can afford it.
- Dual-Mode Sanding with a gear-driven, aggressive mode for rapid stock removal or polishing and random orbital mode for fine sanding.
- Jetstream dust extraction design delivers highly efficient dust removal, resulting in cleaner air, better finishes, and longer abrasive and pad life.
- FastFix tool-free backing pad changing system allows the sander to adapt to different surfaces and tasks with appropriate pads.
- Compact Size with a compact form and a 5″ pad, the RO 125 delivers performance to even the tightest of places.
- MMC electronic controls deliver soft-start, step-less variable speed control, constant speed under load, and thermal and overload protection.
- Weight : 4.4 lbs.
- Dust extraction
- FastFix pad change
- MMC electronics
- Edge protector
- 13″ Plug-It power cord
Like the Bosch 1250EVS (reviewed above), the Festool 571782 RO 125 FEQ, is also a dual-mode sander. So it can be used as an orbital or random orbital sander. As we would expect from Festool, this is probably the ultimate multi-function compact sander for detailed finishing, rapid aggressive sanding, and perfect polishing. It sort of goes without saying, that this is the most expensive in its class – Festool always is. Though if you go to any top woodworking or auto body shop, you’re likely to find at least one (if not several) Festool sanders at work. This is a brand that has earned a reputation for the best saws and sanders, so they are certainly worth paying for.
Practicality, ease of use, and exceptional durability. The compact Festool Rotex has it all. For a small sander, this model has heaps of power from a 500W (4.1A) electric motor. MMC Electronic controls ensure step-less variable speed, soft starting, and constant torque under load. It also includes a pad brake. With the addition of multifunction, orbital and random orbital operation, it’s as versatile as it is incredibly capable of undertaking any sanding task.
The 5” disc is a great size, small enough to get into most places, yet reasonably large for sanding large flat expanses. The sanding stroke is ⁹⁄₆₄”. The handy edge protector can be fitted easily and prevents one from gorging into the material when working along an edge. The pads are quick and easy to change, making it ideal for the busy craftsman with no time to waste.
This is a very smooth sander to use, like any Festool product. Vibration is barely noticeable and the soft grips provide excellent control with one or two hands. It’s also very light at 4.2 LBS. The 1⅟₁₆” dust port is assisted by a Jetstream design which is very effective. A 13’ power cord is another great convenience. As with any Festool product, the orbital sander comes with a tough and very practical carrying case.
Anyone who’s looking for the best multi-function orbital sander in this compact size, will get exactly that in this Festool gem. Yes, it is expensive. You’re always going to pay for quality like this. In the end, if you’re not prepared to compromise on quality and engineering brilliance, this is going to be tool for you.
¼ Sheet Orbital Sander with Paddle Switch Actuation.
Ideal for : Finish sanding and detail work.
- Paddle switch for natural sander actuation
- 2.0-amp power and 16,000 OPM for fast material removal and smooth finishes
- High-performance dust collection to provide a clean work surface
- Convenient paper clamps for ease of use when changing sandpaper
- Provides 270 degree flush sanding clearance
- Tri-layer filtration
- Soft grip paddle switch
So far, we’ve looked at the best orbital sanders for those looking for a hardworking machine for the professional environment and more industrious DIY jobs. But what about the weekend hobbyist? There’s no need to spend masses of cash on a sander that’s only going to be used occasionally. Enter the Black & Decker BDEQS300. This is, arguably, the best cheap orbital sander there is. Black & Decker tools are not always considered the best for professionals who use them on a daily basis. But for the home shop, this may be one of the most popular brands. Quality is of a very high standard for this class of sander, as is its design and function.
Unlike the others, that use sanding pads, the Black & Decker model use a ¼ sheet. This makes it more time consuming to fit the sandpaper to the machine. You have to cut the paper to the correct size and then slot it into position using spring loaded clips. While this isn’t as convenient as quick-fitting pads, it does save a lot on paper. Sheets of sand paper are way cheaper than discs. If you’re in a professional environment, where time is money, this isn’t actually worth it. Though when working at home, spending a little extra time changing sandpaper isn’t a big deal. There was a time when just about all orbital sanders used this method and, back then, no one complained. It’s just the way it was.
With a 2A motor, the Black & Decker is not the most powerful. Though it still handles quite bit with 16,000 OPM. It comes with a dust collection bag, albeit rather small. Though this smaller bag, which more like a filter canister, won’t get in the way. So this is probably a good thing. The grip is good and the handles are comfortable. Though a machine like this, won’t have the same sophisticated anti-vibration systems as the expensive sanders.
For years, I used very similar sanders from Black & Decker and found them to be very competent machines. It’s only after using more sophisticated orbital sanders that one finds this type of tool to be lacking. If you’re a beginner and can’t yet afford a high-end orbital sander, or simply don’t want to spend too much, the Black & Decker BDEQ300 is an excellent choice. There’s nothing fancy about this tool, but it will get the job done and will continue to do so for many years. For this price, I can’t see you getting anything close to the type of quality that this tool offers.
Makita BO5041K — 5″
Variable speed. One of the Best Random Orbit Sander that is both well-made and affordable.
- Smooth and fast sanding with 3.0 AMP motor
- Variable speed control dial (4,000-12,000 OPM) enables user to match the sanding speed to the application
- Ergonomic rubberized palm grip and handle for improved operator comfort
- Adjustable front handle allows for sanding in corners and confined areas
- Large two-finger trigger switch with conveniently located lock-on button for continuous use and increased operator comfort
- Large 1/8″ random orbit action for fast and super smooth sanding provides a swirl-free finish
- Pad control system for controlled pad speed upon start-up
- Efficient through-the-pad dust collection system for a cleaner work environment
- Pad brake engineered for increased performance and reduced gouging
- High capacity dust collection system with built-in vacuum port adapter for improved dust collection
- Uses quick-change 5″ (8-hole) hook-and-loop abrasive paper
- Oversized sealed-ball bearing construction for longer tool life
- Double insulated
One thing I can say about Makita tools is that are virtually indestructible. I’ve dropped mine from many a high roof and continued using them without a problem. Along with the great engineering that goes into all Makita products, it’s little wonder that so many contractors around the world swear by these tough and incredibly competent tools. The Makita BO501K can stand proudly amongst any of the best orbital sanders at the high end of the market. This is a random orbital sanders and is, therefore, best for fine finishing work. It’s not designed for rapid removal, or aggressive sanding. For its purpose-built design, the nifty little Makita performs incredibly well.
As far as durability is concerned, this tool is every bit a true blue Makita. The 3A motor makes uses of an oversized sealed ball baring and the machine is double insulated. It’s perfectly protected from dust and moisture. Combine this with the overall rugged construction, and you have a reliable and dependable tool for life. No matter what you throw at it, the Makita BO5041K is going to keep on working.
The large two finger variable speed trigger (with a locking mechanism) provides perfect control and minimizes operator fatigue. This gives you a speed of 4000 – 12,000 OPM with a ⅛” orbit diameter. Ease of use is further enhanced with superbly low vibration levels of only 3.5 M/S² and very comfortable handles. The front handle can be adjusted so as to make it easier to get into awkward places. It has a very reasonable weight of only 3.5 LBS. This is remarkable for a tool built this tough, Makita tools often tend be on the heavy side due to the over-engineering and heavy-duty materials used.
The round pad uses 5” hole and loop pads (8-hole). Integrated through-pad dust collection makes for superb air quality through a dust port that can be connected to a shop vacuum system. It has a pad brake, as well as soft start and power management that maintains constant torque under load. The kit includes a dust bag and a durable carrying case for safe storage and transportation.
It’s clear that the Makita BO5041K is one of the very best random orbital sanders that you can get. Legendary Makita durability and top-notch after sales service is what has made these tools so popular. I would have a tough time choosing between this sander and the DeWalt alternative. Both brands have a lot going for them, second only to the more expensive offerings from Festool. At least, that’s my opinion on the matter.
Festool 571823 RO 90 FEQ Rotex Sander
- Switch from sanding with a round pad to a delta-shaped pad in seconds, no tools required
- Aggressive sanding mode is gear-driven and allows quick removal of material or stubborn finishes
- Random orbital mode provides astonishing finish sanding results with ease
- Polishing mode and accessories offer the ability to product a brilliant, gleaming shine on nearly any surface
- Lightweight, ergonomic design well-suited for tight spaces and extended use
The Festool RO 90 Rotex multi-function sander is a smaller, slightly less powerful version of the Festool that was reviewed above. It has the same ability to function as an orbital, random orbital sander, or for polishing. All the other amazing stuff that is incorporated into the design of the bigger Festool model can be found on the smaller model too.
This one has a distinct advantage in that it has interchangeable pads. For fast work on wide spaces, it has a round pad, using 3.5” diameter discs. For working in corners, there’s an additional delta pad with a sharp triangular point that allows you to work with perfect accuracy in every situation. Changing the pads or sanding discs is quick and easy with no tools required.
The lower power of 400W won’t affect the working abilities as it’s a smaller machine (3.5” discs as opposed to 5” for the larger model). So whether it’s heavy-duty aggressive sanding or fine polishing you’re after, the RO 90 will do an exceptional job with a ⅛” sanding stroke.
Like the bigger Festool, this one has very comfortable handles with low vibration, soft starting, constant power under load, and a pad brake. It weighs a mere 3.3 LBS and is very easy to use. Dust collection is up there with the very best and it has 1⅟₁₆” diameter port for a vacuum hose or dust bag. It also has the same edge protector as the larger model.
For detailed work in any space, the Festool RO 90 is the perfect orbital (Rotex) sander for the job. Its compact size and the extra delta pad allow this multi-function orbital sander to get into places where others can’t. Allowing you to do the most detailed sanding with absolute precision. It goes without saying, that quality is indisputable. Festool are famous for manufacturing tools of the utmost high standard in every aspect of their design and the materials used.
Bosch ROS65VC-6 — 6″
120V, One of the best Random Orbital Sander & polisher. Professional-grade quality, built-to-last.
- Vibration control – Bosch-exclusive suspension system minimizes vibration for superior handling and maximum comfort
- Two dust-collection systems – Microfilter dust canister with integrated paper filter and screw-off cap or vacuum hose connection with airflow control
- Sanding versatility – for fast stock removal and/or a smooth, well-blended finish
- Powerful 3.3-amp motor with variable-speed dial, (5,500-12,000 OPM) to match speed to workpiece and task
- High-performance soft microcellular backing pad – conforms to contours, provides a fine finish
- Integral pad-dampening system – helps prevent swirl marks for consistent fine finish
- Rugged die-cast aluminum gear housing with exclusive dual-bearing pad mount – long-life design eliminates wobble and vibration
- Microfilter dust canister with integrated paper filter
- Multiple ergonomic grip positions prevent fatigue – front handle removes easily for sanding in tight spots
- Trigger with lock-on button — for extended periods of use
- Accepts 6-in. backing pads (6-hole) and 5-in. backing pads (8-hole)
Makita is often my first choice when comparing power tools, 90% of the time I’m torn between the DeWalt or Makita versions of a similar tool and it’s never an easy decision deciding which is best. Though every now and then, there’s another option thrown into the mix, making the decision even tougher. This is often a Bosch tool and, in this case, I have to admit that the Bosch ROS65VC-6 is a worthy rival to the Makita RO 90 random orbital sander. I’d go as far as to say it may the best random orbital sander in this size option.
This too, is a large sander designed specifically for the best results when performing fine sanding and polishing jobs with great efficiency and speed. The Bosch has a slightly more powerful motor (3.3A vs 3A for the Makita). It can also accommodate larger sanding discs with the option of interchangeable backing pads – either 5” 8-hole, or a 6” 6-hole pad.
The Bosch machine is also designed for ultimate durability and low vibration at the handles and the pad. The die-cast aluminum gear housing and dual-bearing pad mount make this sander extremely durable and provide an incredibly stable base for the pad. This, combined with a very effective pad dampening system and microcellular backing pads, delivers an ultra-smooth finish without any swirl. That’s exactly what we want from a random orbital sander. Bosch supply both soft and hard H&L backing pads for this sander in both sizes (6” or 5”). The hard pads are excellent for efficient sanding on flat surfaces with the best speed and the soft pads are ideal for working on contoured surfaces.
Great anti-vibration technology and well-padded handles are used to maximize user comfort, this is quite remarkable at less than 2.5 M/S². A removable front handle gives great control when working fast, whilst being able to work in more confined areas when the handle is removed. The sander comes with a micro-filter canister that does an excellent job of providing really clean air in your working environment. The compact filter won’t impeded your ability to work in small spaces. You can also hook up a vacuum to the dust port if needed. Using a vacuum will eliminate the need to empty the canister as often – this is the only drawback to compact dust removal systems.
This Bosch random orbital sander as is as easy and convenient to use as any I’ve seen. It has all the important electrical technology – soft start, a pad brake, and a power management system that keeps the speed constant as the working conditions change. A variable speed dial and a great trigger with lock-on give you ultimate control over the orbit speed – 5500 to 12,000 OPM with a ⁵⁄₃₂” orbit diameter.
What an incredible machine! The Bosch ROS65VC-6 has everything I’d want in a 5” or 6” random orbital sander. It has the power to handle anything. User comfort is exceptional with extremely low vibration levels and it’s built to last. The superior engineering that’s gone into the Bosch not only makes it incredibly durable, but also enhances the performance. This sander is going to give you a perfect finish for the best fine sanding and polishing.
More about Electric Sanders
If you’re buying a sander for the first time, it would be helpful to get some advice on how to go about choosing the right tool for your needs. This is what I intend to do in this section. I’ll cover sanders in general, concentrating on orbital sanders in more detail. So you should get the answer to any question you have about these tools here. The most frequently asked question regarding these tools is: what’s the difference between an orbital sander and a random orbital sander? So I’ll give you a clear definition of the two, enabling you to know which might be your best option.
Types of Sanders —
We begin distinguishing types of electric sanders by dividing them into two main categories: belt sanders and orbital sanders.
Belt sanders are large powerful machines, designed to remove the greatest amount of material. These sanders use a continuous loop of sandpaper known as a belt. The sandpaper is moved along two rollers over a flat base to create an even flat surface. A belt sander is used when very aggressive sanding is required. When the wood has particularly rough, with an uneven surface, you’ll use the belt sander to flatten it to an even level. The finish is rough, so you’ll need to finish it by hand or with an orbital sander. For large surfaces that need a lot of material removal, a belt sander is the fastest way to achieve the desired result.
Orbital Sanders are smaller devices, ranging from really small machines that you can use with one hand up to larger models for quicker work on a greater surface area. They will use a finer grit sandpaper than belt sanders for a smother finish. The sanding pad rotates in a circular motion, but orbital sanders are not all the same.
Regular orbital sanders have a sanding pad that constantly rotates in the same direction. This makes them more efficient at removing a thicker layer from the surface, but they don’t provide a perfectly smooth finish. Because the orbit is always in the same direction, we normally end up with swirl. This is fine circle-shapes scratches that are left behind as we work.
Random Orbital sanders are used in the final stages of finishing wood and metal surfaces. By changing the orbit pattern randomly, this eliminates swirl and provides a very smooth surface. Polishing pads can be used to provide a mirror-like finish. Random orbital sanders remove less material and won’t flatten the surface as fast as a regular orbital sander. They are, therefore, only used for in the final stages to create the smoothest surface.
For the ideal finish in the least amount of time, one would start by using a belt sander to for the initial removal of rough uneven textures in the wood. An orbital sander would then be used to remove the deeper scratches created by the belt sander. We would then use a random orbital sander for the final finish.
Dual-mode orbital sanders can switch between a regular orbit and a random cycle. They can do the job of both an orbital and random orbital sander. This eliminates the need for two tools.
What size orbital sander do you need?
Orbital sanders have pads that range from about 3-inches up to about 6-inches. A large sander will obviously save time when you’re sanding full boards, large tables and other flat surfaces. They are not good for sanding detailed molding and getting into small areas like louvers. Essentially, they are the best for faster work on a flat surface.
Smaller orbital sanders are the best for detailed work in small spaces. An auto body shop will usually have a variety of sizes. Similarly, carpentry shops that do a lot of ornate detailing will also have several different size orbital sanders. The shape and density of the pad will also change, depending on how you use these tools.
A soft pad allows the sandpaper to adapt to uneven surfaces and are the best for rounded edges and most auto body work. A hard pad allows one to get an even finish on flat surfaces.
Most sanding pads are round and this allows them to cover the biggest area most effectively. However, when working into corners, a triangular tip will mean that you can work right up to the edge and into tight corners.