Match belt size and amp rating to your work — a 4 x 36 in. belt / 6 in. disc combo covers most home shops; 6 x 48 in. belts are for heavy stock removal.
Belt size decides what a machine can do, and everything else follows. Most US bench-mounted combos fall into two camps: 4 in. x 36 in. belt with 6 in. disc, or 6 in. x 48 in. belt with 9 in. disc. Picking wrong means a sander that stalls on wide boards or hogs space.
Specs come from current manufacturer documentation, including Genesis Power Tools’ 4 x 36 belt/6 in. disc sander page and JET’s combo sanding unit documentation.
What Belt Size Do You Actually Need?
Belt size controls how wide a workpiece you can sand and how fast the machine removes material. Current benchtop combos use four formats: 1 x 30 in., 1 x 42 in., 4 x 36 in., and 6 x 48 in.
- 1 x 30 in. and 1 x 42 in. — compact hobby and knife-sharpening setups, light precision work, small footprint.
- 4 x 36 in. — the balanced home-shop pick; wide enough for furniture parts, aggressive enough for edge work.
- 6 x 48 in. — heavier-duty bench format for wider workpieces and sustained stock removal.
Discs follow the same logic: combos run 5, 6, 8, or 9 in. discs, handling square-end work and curves the belt can’t reach. Kalamazoo Industries builds 1 x 42 in. industrial belt sanders for the smaller-format niche.
How Much Motor Power Is Enough?
A bigger amp or horsepower rating helps, but belt speed, table size, and tilt range change how useful a machine feels day to day. Cited inputs on benchtop combos span 2.1 amps on a small 1 x 30 in. unit up to 5.0 amps on a 4 x 36 in. / 6 in. disc machine, with the JET JSG-96 (model 708595) rated at 3/4 HP.
Speed tells a similar story. The Genesis unit runs a 1,900 FPM belt and 3,600 RPM disc on 120V~, 60Hz, 4.3A. The JET JSG-96 runs 2,258 SFPM on the belt and 1,725 RPM on the disc at 115V, 60Hz, 1Ph — the JET moves material faster on the belt but turns a slower, larger disc.
Amps alone won’t tell you which machine suits your bench: a 5.0-amp motor on a small belt and a 3/4 HP motor on a 6 in. belt are built for different jobs. Tilt range matters too — current units offer 0–45° to 0–90° of belt tilt, with table tilt up to 45°.
| Model Spec | Genesis 4 x 36 Combo | JET JSG-96 (708595) |
|---|---|---|
| Belt size | 4 in. x 36 in. | 6 in. x 48 in. |
| Disc size | 6 in. | 9 in. |
| Motor rating | 120V~, 60Hz, 4.3A | 3/4 HP, 115V, 60Hz, 1Ph |
| Belt speed | 1,900 FPM | 2,258 SFPM |
| Disc speed | 3,600 RPM | 1,725 RPM |
| Tilt range | 0°–90° belt, 0°–45° table | 0°–45° belt |
| Net weight | 39 lb | 91 lb |
Belts, Discs, Power, and Dust Collection
Abrasive sizes are not universal — belts and discs come in incompatible formats, so match the exact belt width and length and disc diameter to your model before ordering replacements.
Power compatibility is the other pre-purchase check: these are 120V/60Hz machines built for the US market — confirm before buying, especially on imported listings.
Dust collection is part of safe setup. JET’s documentation lists a 4 in. dust chute diameter and separate belt and disc tables, reinforcing that table size and a real dust port belong on your checklist. Fine sanding dust is a health issue in a closed shop, so plan a shop vac or collector connection from day one.
Once you’ve settled on belt size and confirmed specs, comparing tested machines side by side is fastest — our roundup of the best benchtop belt sanders walks through options across each belt format.
Before buying, verify six things: amps or HP, voltage, belt size, disc size, tilt range, and dust port diameter. Those six numbers tell you more about capability than any headline spec.
FAQs
Is a 4 x 36 in. belt big enough for furniture work?
For most home-shop furniture and edge work, yes. A 4 x 36 in. belt handles typical board widths and gives you a 6 in. disc for end grain and curves. Step up to 6 x 48 in. only when you regularly sand wider workpieces or need sustained, aggressive stock removal.
Can I use any belt or disc on my sander?
No. Abrasive formats are not universal, and mixing sizes will either not fit or run unsafely. Always match the exact belt width and length plus disc diameter to your machine’s model number before ordering replacements, then confirm power and speed specs align.
Does a higher amp rating always mean a better sander?
Not by itself. Belt speed, table size, and tilt range affect day-to-day usefulness just as much. A 5.0-amp motor paired with a small belt and a 3/4 HP motor driving a 6 in. belt are built for different jobs, so compare full specs rather than amps alone.
References & Sources
- JET. “JET Combo Sanding Unit” Documents the JSG-96 belt/disc specs, 4 in. dust chute diameter, and separate belt and disc tables.
- Kalamazoo Industries. “1SM 1 x 42 Inch Industrial Belt Sander” Supports 1 x 42 in. belt sanders being marketed for smaller-format work.
- Genesis Power Tools. “4 x 36 Belt / 6 Disc Sander” Source for the Genesis 4 x 36 in. / 6 in. disc specs, speeds, and tilt range.
