Belt sanders are used in the beginning of the sanding process. They are not used for fine woodworking, instead they are used for heavy duty tasks, the initial rough sanding. Their job is to make a surface that smooth enough so that a random orbital sander to do the fine sanding. A belt sander is much more powerful than most other sanders. They have a lot of torque so be careful, they can quickly tear through a piece wood.
Stationary belt sanders tend to be larger and more expensive than the handheld models. The stationary model is suited for heavy-duty tasks done by professional. For all normal DIY tasks, a handheld belt sander will be good enough. You can also buy a combined disc and belt sander, which due to their size are stationary sanders.
Given the power of belt sanders, you generally want one with variable speed. This makes it possible for you to control how fast the belt rotate. Since belt sanders often make a lot of dust, a sander with a dust bag is a very good to have. That said, some dust will always escape so wearing a mask is advisable.
The size of the belt is given as X inches by Y inches, there X is the width and Y is the length of the belt.
We recommend the following belt sanders:
The Best Belt Sander: Makita 9403 4″ x 24″ Belt Sander with Cloth Dust Bag and 4-Inch x 24-Inch Abrasive Sanding Belt
Our Rating: 4.75/5 
Makita make a couple of excellent belt sanders, and the one we like the most ist the Makita 9903 Belt Sander. It is very versatile belt sander. It is very quiet but still a powerful. It is small and light weight, making it easy to handle. It has a long power cord (16,4 foot) and the dust collection works well. You clamp upside down in a wood worker’s bench vice and use it as a stationary sander. It is pretty expensive but you get what you pay for. All in all, the Makita 9903 is an excellent and very versatile belt sander.
You can buy the Makita 9903 8.8 Amp 3-Inch-by-21-Inch Variable Speed Belt Sander from Amazon.com, taking advantage of Amazon’s low prices and excellent customer service. Click here to go to Amazon.com
The Best Value For The Money: WEN HB3185 5-Amp 3-by-18-Inch Variable Speed Belt Sander
Our Rating: 4.25/5 
Good belt sanders are generally expensive. Buying factory-reconditioned tools can be risky but also a way of saving money. The Factory-Reconditioned Skil 7500-RT Belt Sander is a good sander, powerful enough for all normal tasks around the house and fairly light weight. It comes with a Micro-Filter dust canister which collects most of the dust. You don’t get variable speed but the price is very low. If you want a cheap sander, you can not get better value for your money than this. It comes with a one-year warranty, protecting your money. All in all, the Factory-Reconditioned Skil 7500-RT is a good sander and it is incredibly cheap, you get excellent value for your money.
You can buy the WEN HB3185 Belt Sander at Amazon.com, taking advantage of Amazon’s low prices and excellent customer service. Click here to go to Amazon.com
The Best Powerful Belt Sander: Makita 9403 11 Amp 4-Inch-by-24-Inch Belt Sander with Cloth Dust Bag
Our Rating: 4.75/5
If you need a powerful sander, the Makita 9403 is the right sander for you. Despite its large size, 4-inch footprint, it is fairly light weight. Best of all, it is extremely quiet despite being such a powerful sander. It comes with a long power cord and the dust collection is excellent. It is easy to change belts. No wonder that this is one of the best selling belt sanders. It is quite expensive, but if you need a powerful belt sander, this is the best.
You can buy the Makita 9403 11 Amp 4-Inch-by-24-Inch Belt Sander from Amazon.com, taking advantage of Amazon’s low prices and excellent customer service. Click here to go to Amazon.com
The Best Small Belt Sander: Porter-Cable 371 2 1/2 by 14-Inch Compact Belt Sander
Our Rating: 4.5/5 
Most belt sanders are fairly large but sometimes you need a small and light weight sander. If you need a compact belt sander, then the Porter-Cable 371 is certainly worth a closer look. Given its small size, 2.5 X 14”, it’s not as powerful as the larger sanders but it can handle most tasks anyway. It only weights about 5 lb. It does not have a dust bag but it has a removable dust port to attach a vacuum. One drawback is that the Porter-Cable 371 can get hot if you use it for longer time. But this problem can be minimized by using good sandpaper.
You can buy the Porter-Cable 371K 2 1/2 by 14-Inch Compact Belt Sander Kit from Amazon.com, taking advantage of Amazon’s low prices and excellent customer service. Click here to go to Amazon.com