3" x 21" Surface Conditioning Belts (Non-Woven), 4 PACK
3" x 21" Surface Conditioning Belts (Non-Woven), 4 PACK
Available in stock (49999)
Put a non-woven belt on a hand-held belt sander and it stops being a wood tool: it strips rust and old paint from steel, cleans mill scale off plate, blends welds on site and brushes a satin finish onto stainless sheet without gouging. These 3" x 21" surface conditioning belts fit the most common portable belt sander size, so a fabricator or maintenance crew can do that work with the sander already in the truck.
Each 4-pack is one grade: Coarse, Medium, Very Fine or Ultra Fine. The nylon web is loaded with aluminum oxide grain on a reinforced scrim backing that tracks like a cloth belt and does not stretch, and it can be run wet or dry on steel, stainless, aluminum, titanium, fiberglass and plastics.
- Fits 3 x 21 portable belt sanders from Makita, DeWalt, Bosch, Craftsman, Black+Decker, Bauer, Metabo HPT and Triton
- Turns a wood belt sander into a rust, paint and scale removal tool without changing part dimensions
- Four grades, 40–60 through 320–400 grit scratch, sold four of one grade per pack
- Open web runs cool and does not load with paint or aluminum the way a coated belt does
- Reinforced scrim backing tracks true and survives the tension of a hand-held sander
- Free shipping on orders over $200; bulk pricing on request
Which grade should you buy for a hand-held sander?
A portable belt sander runs fast and puts the operator's weight behind the belt, so grades act a step more aggressive than the same web on a bench machine. Err toward the finer grade.
- Coarse (40–60 grit scratch), brown: stripping rust, old paint, mill scale and weathered galvanizing from steel plate, gates, trailers and structural sections. It removes coatings quickly and leaves the base metal keyed for primer.
- Medium (80–120 grit scratch), maroon: the all-round grade. Blends ground welds into surrounding plate, cleans up a 120 grit coated-belt scratch, preps steel and aluminum for paint or powder coat.
- Very Fine (180–240 grit scratch), blue: the grade for a linear brushed finish on stainless sheet, countertops, backsplashes and aluminum trim, and the grade most buyers reorder.
- Ultra Fine (320–400 grit scratch), grey: final satin on decorative stainless and aluminum, and for cleaning heat tint off a polished part without dulling the polish around it.
If you only buy one pack for general shop and site work, buy Medium. If you are matching an existing brushed stainless finish, buy Very Fine.
Grade guide for stripping, blending and brushing with a portable sander
| Grade | Use it for | Notes |
|---|---|---|
| Coarse 40–60 | Rust, paint, mill scale removal | Fastest; keep the sander moving |
| Medium 80–120 | Weld blending, paint prep | Most versatile grade |
| Very Fine 180–240 | Brushed stainless and aluminum | Long straight passes |
| Ultra Fine 320–400 | Fine satin, heat tint removal | Lightest pressure |
Match the grade to the scratch already on the part. Coming off a 60 grit coated belt, go to Coarse or Medium; coming off 120–220, go to Very Fine.
Which portable belt sanders take a 3 x 21 belt?
- Makita 9903
- DeWalt DW433 and DeWalt DWP352VS
- Bosch 1274DVS and Bosch GBS 75 AE / PBS 75 A (75 x 533 mm)
- Craftsman CMEW213
- Black+Decker DS321 Dragster
- Bauer 57587 (Harbor Freight)
- Metabo HPT SB8V2 / SB8V2M
- Triton TA1200BS (76 x 533 mm)
- Porter-Cable 352VS, as named on our earlier page for this belt
Mounting: release the belt tension lever, slide the belt on, re-tension and set tracking with the sander running and pointed away from you. The web has no direction arrow, so orientation does not matter. Non-woven belts are thicker than cloth belts; if tracking wanders on a worn tracking knob, back the belt a fraction toward the motor side and let it settle. Metric 75 x 533 mm machines take this belt.
How to get the most out of them
- Start the sander off the work. Let it reach speed, then lower the rear roller first and bring the platen down flat. Landing the front roller first on a Coarse belt digs a groove.
- Let the sander's weight do the work. Do not push down. Downward pressure compresses the web, generates heat and tears fibers off the scrim. On aluminum it also smears metal into the belt.
- Keep moving in long overlapping passes. Never stop on the part. On stainless, run every pass in the same direction, end to end, so the brush lines are continuous and parallel; that is what makes the finish look factory.
- Slow it down if you can. If your sander has variable speed, run it at the low end for non-woven. On single-speed sanders use the lightest touch and shorter contact time.
- Stay on flat and gently curved surfaces. The platen is flat; over an inside corner or a sharp edge the belt will round the edge and wear a stripe through the web.
- Clean, dry and store. Blow out the web after paint or aluminum. If used wet, hang it to dry. Keep spare belts out of sunlight and off the damp floor of the truck.
Use it for / don't use it for
Use it for
- Removing rust, old paint and mill scale from steel plate, angle, gates, railings and trailers
- Blending ground welds into surrounding plate on site
- Brushed satin finishes on stainless sheet, counters, hoods and backsplashes
- Prepping steel and aluminum for primer, paint or powder coat
- Cleaning oxidation off aluminum boat rails, truck bodies and extrusions
- Scuffing fiberglass and plastics for paint adhesion
Don't use it for
- Grinding welds flush or removing stock; use a coated zirconia belt first
- Fine furniture sanding; a coated aluminum oxide belt leaves a better wood surface
- Inside corners and sharp edges; the platen cannot follow them
- Producing a mirror; the Ultra Fine belt is a pre-polish, not a polish
Specifications
| Size | 3" x 21" (75 x 533 mm) |
|---|---|
| Abrasive | Aluminum oxide in a non-woven nylon web |
| Backing | Reinforced scrim, stretch-resistant |
| Grades offered | Coarse (40-60), Medium (80-120), Very Fine (180-240), Ultra Fine (320-400) |
| Color code | Brown / maroon / blue / grey |
| Joint | Bi-directional, no arrow |
| Pack quantity | 4 belts, one grade per pack |
| Wet or dry | Both |
| Fits | 3 x 21 portable belt sanders |
| Converted in | Anaheim, California |
| Custom sizes | Made to order in about 3 days |
Frequently asked questions
Will a 3 x 21 surface conditioning belt fit my Makita or DeWalt belt sander?
Yes. A 3" x 21" belt fits the Makita 9903, DeWalt DW433 and DWP352VS, Bosch 1274DVS, Craftsman CMEW213, Black+Decker DS321 Dragster, Bauer 57587, Metabo HPT SB8V2 and Triton TA1200BS, plus metric 75 x 533 mm sanders. Check your sander's belt size in the manual or on the label near the tracking knob before ordering.
Can I remove rust and paint from steel with these belts?
Yes, that is one of the main jobs for a 3 x 21 non-woven belt on a portable sander. The Coarse (brown) grade strips rust, mill scale and old paint down to clean, keyed metal without cutting into the plate the way a coated belt does. Follow with Medium if you want a finer profile before primer.
Which grade do I use to match a brushed stainless finish?
The Very Fine (blue, 180–240 grit scratch) grade produces the linear satin that matches most brushed stainless sheet. Run the sander in long, parallel, end-to-end passes in the direction of the existing grain and do not stop on the panel. For a softer, finer satin use Ultra Fine (grey).
Why does the belt wear out fast on my belt sander?
Almost always pressure. A hand-held sander lets you lean on the belt, which crushes the nylon web against the platen, overheats it and rips fibers off the backing. Use only the sander's own weight, keep it moving, and drop to a lower speed if the tool has one. A properly run belt outlasts a coated belt on the same job.
Can I use these belts wet?
Yes. The web and scrim backing are waterproof, so a 3" x 21" non-woven belt can be run wet with a spray bottle or with a light lubricant on aluminum, as long as your sander is rated for that and its electrics are protected. Hang the belt to dry afterwards; do not store it damp in the pack.
Is the 4-pack four different grades or four of the same?
Each 4-pack is four belts of one grade, Coarse, Medium, Very Fine or Ultra Fine, so you choose the grade at checkout. If you want to try all four, order one pack of each or ask us about mixed quantities and bulk pricing by calling 714-646-3299 or emailing sales@maverickabrasives.com.
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