The question “what is the difference between ANSI 40 and ANSI 41 roller chain” is one of the most frequently asked in chain procurement and maintenance — because the two specifications look similar in catalogues (same nominal pitch, similar applications) but are different products that are not interchangeable on the same sprocket. ANSI 41 chain is lighter, cheaper, and less capable than ANSI 40 chain, and using ANSI 40 sprockets with ANSI 41 chain (or vice versa) causes engagement problems and accelerated wear.
The Key Differences Between ANSI 40 and ANSI 41
| Specification | ANSI 40 | ANSI 41 | Notes |
|---|---|---|---|
| Nominal Pitch | 12.70 mm (0.500 inches) | 12.70 mm (0.500 inches) | Same pitch — the source of confusion between the two types |
| Roller Diameter | 7.92 mm (0.313 inches) | 7.77 mm (0.306 inches) | ANSI 41 roller is slightly smaller (lighter roller) |
| Inner Width Between Plates | 7.85 mm (0.309 inches) | 6.35 mm (0.250 inches) | ANSI 41 is significantly narrower inside — a key identification dimension |
| Link Plate Thickness | 1.52 mm (0.060 inches) | 1.27 mm (0.050 inches) | ANSI 41 uses thinner plates (lighter, weaker) |
| Minimum Tensile Strength | 14.1 kN (3,170 lbf) | 7.7 kN (1,730 lbf) | ANSI 40 breaking load is nearly double ANSI 41 |
| Weight Per Metre | 0.60 kg/m | 0.41 kg/m | ANSI 41 is 32 percent lighter per metre |
| Sprocket Compatibility | ANSI 40 sprockets — specific tooth width | ANSI 41 sprockets — narrower tooth width; not compatible with ANSI 40 sprockets | Not interchangeable — use matched chain and sprocket |
What ANSI 41 Chain Is Designed For
ANSI 41 chain was developed for light-duty applications where the full capacity of ANSI 40 chain is more than required, and where the lower cost and lighter weight provide a practical advantage. The most common applications in Australia: go-kart and light karting vehicle primary drives; garden equipment (ride-on mowers, small tillers, light conveyors); timing drives in light industrial equipment; and light-duty bicycle transmission components where the narrower ANSI 41 profile fits in narrower frame clearances. ANSI 41 chain is a genuine standard — not an inferior or non-standard product — but it is a lighter-duty standard intentionally designed for lower loads.
What ANSI 40 Chain Is Designed For
ANSI 40 chain is the standard industrial specification at the 12.70 mm pitch, found in a very wide range of light-to-medium industrial and agricultural applications: small agricultural equipment (push mowers, walk-behind implements, light conveyor drives); secondary drives in balers, planters, and planting equipment; light industrial conveyors and timing drives; and drive chains in small to medium power transmission applications up to approximately 2 to 3 kW depending on speed.
Identifying Which Chain You Have
To identify whether an unknown chain is ANSI 40 or ANSI 41, measure the inner width between the inner link plates with a vernier caliper. ANSI 40 measures approximately 7.85 mm inner width; ANSI 41 measures approximately 6.35 mm inner width — a significant and easily measured difference. The pitch is the same for both (12.70 mm), so pitch measurement alone cannot distinguish the two. Alternatively, weigh a 10-link section: ANSI 40 weighs approximately 76 grams per 10 links; ANSI 41 weighs approximately 52 grams per 10 links.
Identifying Which Sprocket You Have
Because ANSI 40 and ANSI 41 have different inner widths, their sprockets have different tooth widths. An ANSI 40 sprocket has a tooth width of approximately 7.62 mm; an ANSI 41 sprocket has a tooth width of approximately 6.10 mm. A narrower ANSI 41 chain will fit over an ANSI 40 sprocket tooth but will not engage correctly — the rollers will contact the outer edges of the tooth rather than seating in the tooth root. A wider ANSI 40 chain cannot be forced onto a narrower ANSI 41 sprocket at all — the tooth is too narrow for the chain to fit.
EverPower Roller Chains Australia supplies ANSI 40 and ANSI 41 roller chain with matched sprockets for all Australian light industrial and agricultural equipment. Contact +61 2 9708 3322 or [email protected].
+61 2 9708 3322 | [email protected] | 27 Harley Crescent, Condell Park NSW 2201