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3M Cubitron II File Belts 786F, 3/8 × 13, 1/2 × 18 or 3/4 × 20-1/2 in, 36+ to 80+

3M Cubitron II File Belts 786F, 3/8 × 13, 1/2 × 18 or 3/4 × 20-1/2 in, 36+ to 80+

33437

3M's precision-shaped-grain file belts for spot weld removal, rivet grinding and tight-access prep. 3M says Cubitron II cuts 30% faster and lasts twice as long as conventional ceramic, and runs cooler to limit discoloration and heat stress.

Faster cut (3M)
30%
Longer life (3M)
2x
Grades
36–80+
Belts per carton
10
Choose your size

Belts and sanders

Belt 3M sander Grades here
3/8 × 13 in Mini File Belt Sander 33573 36+, 60+, 80+
1/2 × 18 in File Belt Sander 33575 36+, 60+, 80+
3/4 × 20-1/2 in File belt sanders taking 20-1/2 in belts 36+, 60+, 80+
Why it works

Sharp grain, cool cut

  • Precision-shaped grain. Triangular ceramic grain on a heavy XE-weight backing.
  • Cooler grinding. Less risk of discoloration and heat-related stress cracks.
  • Shop jobs. 3M lists spot weld removal, rivet grinding, brake caliper cleaning, wheel corrosion removal and steering knuckle prep.
Heads up: 3M has replaced this belt. 3M discontinued Cubitron II 786F on May 18, 2026, while supplies last. We still have stock. Its replacement is Cubitron 3, and 3M's 36+ belts become 40+ in the new line.
Specifications

Tech specs

Product 3M Cubitron II File Belt 786F
Sizes 3/8 × 13, 1/2 × 18, 3/4 × 20-1/2 in
Grades 36+, 60+, 80+
Grain Precision-shaped ceramic
Backing XE weight
Pack 10 belts per carton
Replacements Cubitron 3 (e.g. 33479 for 33437, 33480 for 33439)
Pairs well with

Related

Quick answers

FAQ

Which belt fits my sander?

3M's Mini File Belt Sander 33573 takes 13 in belts, and the 33575 takes 18 in belts. Match the belt length to your sander.

Is this belt still made?

3M discontinued it on May 18, 2026. We're selling through our stock; Cubitron 3 is the replacement.

What jobs is it for?

3M lists spot weld removal, rivet grinding, brake caliper cleaning, wheel rim corrosion removal and steering knuckle prep.

How many belts per carton?

10 belts per carton.

Manufacturer documents: 3M Cubitron II discontinuation letter (PDF)

$29.00
$32.59 $29.00
Sale Sold out
Shipping calculated at checkout.
Size
Grit
  • Ships in 1–2 business days from Eugene, OR
  • Free ground shipping over $425 · $9.99 under
  • Free pickup in Eugene, OR — usually ready in 24 hours
  • 30-day returns on unopened, resalable items

In stock

View full details

Technical details

General

Part number
33437
Brand
3M
Product type
File Belts
Variant Variant total Quantity Price Variant total
3M Cubitron II File Belts 786F, 3/8 × 13, 1/2 × 18 or 3/4 × 20-1/2 in, 36+ to 80+
3/8" x 13" / 36+33437
3/8" x 13" / 36+33437
$32.59
$29.00/ea
 $0.00
$32.59
$29.00/ea
 $0.00
3/8" x 13" / 60+33439
3/8" x 13" / 60+33439
$31.63
$29.00/ea
 $0.00
$31.63
$29.00/ea
 $0.00
3/8" x 13" / 80+33440
3/8" x 13" / 80+33440
$31.63
$29.00/ea
 $0.00
$31.63
$29.00/ea
 $0.00
1/2" x 18" / 36+33443
1/2" x 18" / 36+33443
$47.09
$36.30/ea
 $0.00
$47.09
$36.30/ea
 $0.00
1/2" x 18" / 60+33445
1/2" x 18" / 60+33445
$45.65
$35.20/ea
 $0.00
$45.65
$35.20/ea
 $0.00
1/2" x 18" / 80+33446
1/2" x 18" / 80+33446
$45.65
$35.20/ea
 $0.00
$45.65
$35.20/ea
 $0.00
3/4" x 20-1/2" / 36+33449
3/4" x 20-1/2" / 36+33449
$50.44
$38.85/ea
 $0.00
$50.44
$38.85/ea
 $0.00
3/4" x 20-1/2" / 60+33451
3/4" x 20-1/2" / 60+33451
$46.86
$36.12/ea
 $0.00
$46.86
$36.12/ea
 $0.00
3/4" x 20-1/2" / 80+33452
3/4" x 20-1/2" / 80+33452
$46.86
$37.46/ea
 $0.00
$46.86
$37.46/ea
 $0.00
0

Total items

$0.00

Product subtotal

Taxes, discounts and shipping calculated at checkout.