1" x 21" Metalworking Sanding Belts, 24 PACK

Belt files get into the places a grinder cannot: weld toes inside a box section, slots and keyways, casting flash, the inside radius of a bracket. These 1" x 21" metalworking belts are built for that work on air-powered and electric belt files, with the grain chosen for the metal in front of you: ceramic for stainless and hardened steel, zirconia for carbon steel and iron, Zirconia+ (Grinding Aid) for stainless and aluminum that wants to load or burn, and Cloth A/O for the fine finishing grits.

Every belt is converted here in Anaheim, California on a Y-weight poly-cotton backing with heat-treated grain, so it takes the pressure a narrow belt sees at the contact arm without stretching or tearing at the joint. The 24-pack keeps a fab shop or maintenance cart stocked in one grit; run the coarse zirconia or ceramic for stock removal and the aluminum oxide 150–600 for the finish.

• Four grains for metal in one size: ceramic, zirconia, Zirconia+ grinding aid, cloth aluminum oxide
• Y-weight poly-cotton backing takes contact-arm pressure without stretching; runs wet or dry
• 24 to 600 grit covers weld knockdown through pre-polish on one belt tool
• Heat-treated grain built to outlast typical paper or light-cloth file belts
• 24 belts per pack keeps an air belt file station stocked in one grit
• Converted in Anaheim, California; free shipping on orders over $200

Which grain should you choose for which metal?

Pick the grain by the metal and the amount of pressure your tool can put on it. A belt file is a light machine, so grain that only works under heavy load is the wrong buy for most of its jobs.

• Zirconia: the default for carbon steel, mild steel plate, cast iron and general fabrication. It self-sharpens as it micro-fractures under load, so lean on it. Offered 24–120 grit; finer than that, switch to aluminum oxide.
• Zirconia+ (Grinding Aid): the same zirconia grain with a grinding-aid top coat over the grinding aid already in the resin bond. The coating lubricates the cut and pulls heat out of the part, so it is the belt for stainless steel, aluminum, titanium and anything that loads or blues. On a belt file, where you cannot flood coolant, this is the one we reach for on stainless tube.
• Ceramic: the orange-red belt. Sol-gel grain that keeps a near-constant cut rate for its whole life on stainless, hardened and tool steel and nickel alloys. It needs firm, steady pressure to keep fracturing; run it light on a small air tool and it glazes and heats the part instead of cutting. Best on a stout electric belt file or an air tool with the pressure to feed it.
• Cloth A/O: heat-treated aluminum oxide on the same poly-cotton cloth. Forgiving at light pressure, so it suits aluminum, brass, bronze, soft steel and every finishing grit. This is where 150, 180, 220, 320, 400 and 600 live; use it to take out the zirconia or ceramic scratch before paint, anodize or polish.

Old rule that still holds: zirconia and ceramic above 120 grit do not give you a finish, they give you a shiny scratch. Do the finishing on aluminum oxide or a non-woven belt.

Grit guide: steel versus aluminum on a 1" x 21" belt file

Steel and aluminum want different starting points. Steel tolerates a coarse start; aluminum smears and loads a coarse belt and shows every deep scratch afterwards.

Never skip more than one grit. A typical steel sequence on a belt file is 60 zirconia, 120 zirconia, 220 aluminum oxide; on aluminum it is 80, 120, 220 aluminum oxide with the grease stick applied at every grit.

What machines does a 1" x 21" belt fit?

• Air-powered belt files (pneumatic finger sanders and belt tools) built around a 1" x 21" belt. Match both dimensions to your tool's manual; belt-file lengths vary by brand and a 21" belt will not tension on an 18" or 24" arm.
• Electric belt file sanders that specify a 1" x 21" belt. Our sibling 1-1/8" x 21" metalworking belt fits the Makita 9031 class; if your tool calls for 1-1/8", buy that width, not this one.
• Small bench belt sanders and shop-built jigs set up for a 1" x 21" belt, common for deburring small parts and sharpening.

Tracking and direction: check the inside of the belt for a direction arrow before mounting. If there is one, run the belt that way or the joint will lift; if there is none, the belt runs in either direction. Set tension before you start the tool, run it for a second off the work and adjust tracking so the belt rides centred on the contact arm. If you need a different length for an unusual tool, we make custom sizes in about 3 days.

How to get the most out of it

1. Match pressure to the grain. Zirconia and ceramic need real pressure to keep fracturing and staying sharp; aluminum oxide needs less. If a ceramic belt stops cutting on a small air tool, it is glazed from too little load, not worn out.
2. Keep the belt moving. Dwelling on one spot with a narrow belt is the fastest way to blue stainless or wash out a flat. Work in overlapping strokes and let the belt's speed do the cutting.
3. Slow down for aluminum, speed up for steel. On a variable-speed tool, drop belt speed for aluminum, brass and bronze and rub a grease stick on the running belt; it stops the grain loading and the part heating. Run steel at full speed.
4. Run wet when you can. The poly-cotton backing tolerates coolant, so on a wet-capable tool a mist or drip keeps the edge cool and the swarf off the belt.
5. Clean loaded belts. On aluminum oxide, a crepe belt eraser held lightly against the running belt clears packed aluminum and paint. On zirconia, lower pressure or switch to the grinding-aid belt if it keeps loading.
6. Manage dust and sparks. Use a dedicated metal-rated collector or wet collection; steel dust in a wood-dust collector is a fire risk. Eye and face protection and gloves for the burrs.
7. Store them right. Hang the belts or leave them loosely rolled, away from humidity and sunlight, and let cold belts come to room temperature before running them.

Use it for / don't use it for

Use it for

• Blending and deburring TIG and MIG welds in tight corners, tube frames and box sections
• Removing casting flash and parting lines on iron, steel and aluminum
• Deburring slots, keyways, punched and laser-cut edges
• Sharpening and reshaping tools, mower blades and chisels on a belt file
• Graining stainless and aluminum parts with the 150–600 grit aluminum oxide belts
• Cleaning rust, scale and old coatings off steel before welding or paint

Don't use it for

• Expecting ceramic to cut at light pressure on a small air tool; use zirconia or aluminum oxide there
• Finishing with zirconia or ceramic above 120 grit; switch to Cloth A/O or a non-woven belt
• Sharing a dust collector between wood and steel grinding
• Tools that call for a different length or width; measure before ordering

Specifications

Frequently asked questions

Related products and guides

• 1-1/8" x 21" Metalworking Sanding Belts, 20 pack (Makita 9031 size)
• 1/2" x 18" Surface Conditioning Belts for bandfiles
• Grease stick for sanding belts (aluminum and non-ferrous)
• All narrow sanding belts
• Custom sanding belts made to order in about 3 days