The Tooth Form Follows the Chain
A sprocket's tooth form isn't arbitrary — it's defined by the chain pitch and roller diameter, so once we know your chain, the geometry follows. That's why a worn or even partly broken sprocket can be reproduced exactly: we work from the chain standard, not the damaged teeth. The dimensions that then matter for fit are the bore, keyway and overall width.
Custom Sprocket Specifications
| Attribute | Capability |
|---|---|
| Chain standards | ANSI 25–100+, ISO 06B–16B+ |
| Strands | Single, duplex, triplex |
| Materials | 1045 / 4140 steel, stainless |
| Teeth | Induction- or case-hardened for wear |
| Bore | Plain, keyed (DIN 6885), set-screw, taper bush |
| Styles | Hub, platewheel, double-pitch, idler |
Chain Sizes & Pitch Diameter — How to Identify Your Sprocket
A sprocket is fully defined by its chain size (which fixes the pitch) and its tooth count. ANSI chain pitch runs in ⅛-inch steps — the chain number ÷ 8 gives the pitch in inches:
| ANSI no. | Pitch | ISO equiv. |
|---|---|---|
| 25 | 1/4" (6.35 mm) | 04C |
| 35 | 3/8" (9.525 mm) | 06C |
| 40 | 1/2" (12.7 mm) | 08A |
| 50 | 5/8" (15.875 mm) | 10A |
| 60 | 3/4" (19.05 mm) | 12A |
| 80 | 1" (25.4 mm) | 16A |
The pitch diameter then follows from the pitch (P) and tooth count (N): PD = P ÷ sin(180° / N) (per ASME B29.1). So with the chain identified and the teeth counted, the sprocket is fully specified — which is exactly how we reproduce one. The surest way to confirm the chain is to send a short length of it with the worn sprocket.
How We Make / Reproduce a Sprocket
- From specs: chain size + tooth count + shaft bore — the rest is derived from the standard.
- From a sample: we identify the chain pitch from the sprocket and a length of chain, then rebuild it (see reverse engineering).
- Harden: teeth hardened for wear while the bore stays machinable.
Material & Hardness
Most sprockets are machined in 4140 or 1045 steel with hardened teeth for chain-wear life; stainless suits wet or corrosive lines. Light-duty or quiet drives can use nylon. Tooth form, bore and keyway are verified on inspection.
Obsolete sprocket? Send the worn sprocket and a short length of the chain it runs. We identify the pitch, rebuild the tooth form, and machine new ones — one or a batch. No drawing required.
Frequently Asked Questions
Yes — give us the chain size (ANSI 40/50/60 or ISO 08B/10B/12B) and tooth count, or send the old sprocket and a length of chain. The tooth form follows the chain pitch and roller diameter.
Yes — steel sprockets with induction- or case-hardened teeth for wear life, bore and keyway left machinable. Stainless for corrosive lines.
ANSI 25–100+ and ISO 06B–16B+ single or multi-strand, a wide range of tooth counts, plus idlers and double-pitch sprockets.
All available — keyway to DIN 6885, set-screw flats, or taper-lock bush bore to your shaft.
Quote a Custom Sprocket
Chain size, sample or drawing — all accepted. Reply in 24h.