20B roller chain
1¼″ pitch (31.75 mm), minimum breaking load 9,694 kgf (95.1 kN), cut to your exact pitch count with the connecting link fitted, from our Malvern warehouse.
Held in UK stock as simplex, duplex, triplex; same-day dispatch on stocked variants ordered by 1pm.
20B dimensions
Standard minimums and nominal dimensions: the same figures as our BS roller chain range table. Duplex and triplex share the pitch, roller and plate dimensions of the simplex chain.
| Chain | Pitch (mm) | Inner width (mm) | Roller Ø (mm) | Plate height (mm) | Pin Ø (mm) | Min breaking load kgf | Weight (kg/m) |
|---|---|---|---|---|---|---|---|
| 20B-1 | 31.75 | 19.56 | 19.05 | 26.42 | 10.19 | 9,694 (95.1 kN) | 3.85 |
Availability by variant
| Variant | Availability |
|---|---|
| Simplex | UK stock |
| Duplex | UK stock |
| Triplex | UK stock |
| Stainless steel (simplex) | To order |
| Stainless steel (duplex) | To order |
| Hollow pin | Enquire |
| Hollow pin, stainless steel | Enquire |
Sizes marked "Enquire" feed our bespoke service — special requirements are normal work here.
20B variants and builds
- Attachment versions — A, K, SA and SK platforms built to your spacing in Malvern
- Straight-plate version (20BGL) — flat side bars for surfaces that slide, same sprockets
- Matched sprockets — pilot bore, taper lock and finished bore to suit 20B
Pitch, roller diameter and inner width name almost any roller chain: the identification guide shows where to measure, and the BS–ANSI cross-reference catches lookalike sizes.
Straight answers
Will 20B chain run on my existing sprockets?
Yes: 20B is a standard British Standard (ISO 606) size, so any chain made to the standard runs on 20B sprockets. Simplex, duplex and triplex share the same pitch and roller diameter; a multi-strand chain just needs the matching multi-strand sprocket, which we supply machined to our specification.
What length can I order 20B chain in?
Any length: we cut to your exact pitch count and fit the connecting link, with a cranked link for odd counts, so the chain arrives ready to fit. Your made-up spec stays on file, so a reorder is a phone call.
How do I check a chain I have is 20B?
Measure the pitch (pin centre to pin centre, 31.75 mm for 20B), the roller diameter (19.05 mm) and the inner width (19.56 mm). Our chain identification guide shows the three measurements, and a photo with a tape measure in shot settles anything unusual.
Is there a ANSI equivalent of 20B?
Sometimes chains of the two standards share a pitch but differ in roller diameter or width, so they are not automatically interchangeable. Check the BS–ANSI cross-reference guide before substituting, or send us both designations and we will confirm.
Need 20B chain cut to length?
Send the pitch count or the old chain's length and we'll quote it made up, links fitted, with sprockets to match.