Sprockets and Roller Chains Machined to Drawing

A chain drive is only as good as the sprocket that carries it. Tooth form decides how the roller seats, pitch accuracy decides whether the chain wears evenly, and the bore and keyway decide whether the sprocket runs true on the shaft at all.

PinyiGear machines drive, conveyor, duplex and custom sprockets — 9 to 80 teeth, pitch 6.35 to 50.8 mm — with induction-hardened flanks and bores cut to the drawing. Matching A and B series roller chains can ship with the order.

Choosing the sprocket type

The first question is what the chain has to do. A drive sprocket transmits power and the priority is tooth accuracy and wear life; a conveyor sprocket carries load at low speed and the priority is strength and resistance to abrasive material; a multi-strand sprocket exists because the power will not fit through one chain.

Working ranges

Two parameters decide most of the geometry. Tooth count sets the wrap angle and the chordal action — fewer teeth mean a larger speed variation per tooth and more wear on the chain. Pitch sets the chain size and the load a strand can carry. Everything else follows from the chain chosen.

Standards and interchangeability

ANSI and DIN/ISO chains are dimensionally similar but not identical, and a sprocket cut for one will not run correctly on the other. The usual series:

• ANSI: 40, 50, 60, 80, 100, 120, 140, 160, 180, 200
• DIN / ISO: 08A, 08B, 10A, 10B, 12A, 12B, 16A, 16B, 20A, 20B

A and B series differ in roller width and, at some sizes, roller diameter — an 08B chain does not interchange with an 08A chain. When a sprocket is supplied without a stated standard, the first thing that has to be settled is which chain it will run.

Roller chains

Simplex, duplex and multiplex chains in both A and B series, matched to the sprocket order.

Chain and sprocket are a pair in the same sense that a gear and pinion are. Buying them together removes the argument about which side caused the wear pattern.

Machining

Sequence: tooth cutting first, then boring and facing, then induction hardening of the flanks, then the keyway and set-screw holes. That order matters — cutting the keyway before hardening means the keyway distorts, and hardening after boring means the bore has to be finished again.

Inspection

• Tooth profile and pitch — measured against the chain standard, not just against a drawing dimension
• Runout between the bore and the pitch circle, which is what decides whether the chain runs true
• Bore and keyway — size, position, and fit against the shaft
• Hardness at the tooth flank
• Concentricity between hub and tooth ring on welded or bolted constructions

A sprocket that measures correct on tooth count and pitch but has runout between bore and teeth will load one side of the chain and wear it out early. Runout is the number worth asking for.

Where they are used

General drive systems, conveying machinery, packaging and filling lines, agricultural equipment, high-power drives where a multi-strand chain replaces a gearbox, and replacement sprockets for equipment whose original part is no longer supplied.

Related transmission parts

Racks, sprockets, timing pulleys and couplings can be supplied together, which matters when a machine has several drive types and the customer would rather not coordinate four suppliers.

What to send

• Sprocket drawing (PDF, DXF, STEP, DWG), or chain standard plus tooth count
• The chain model, if the sprocket must match an existing chain
• Bore, keyway and set-screw details
• Material and heat treatment if fixed
• Quantity and whether the order is a prototype, a first batch or repeat production

Send a sprocket drawing for quotation

FAQ

Can you cut a sprocket to match a chain I already have? Yes — send the chain model or a short sample. The tooth form has to match the roller diameter and pitch of that specific chain, so the chain is the reference, not the drawing alone.

Which standard should I specify? Whichever chain you will run. ANSI and DIN/ISO differ in roller width and sometimes roller diameter, and a sprocket cut for one will not run correctly on the other.

Is hardening necessary? For drive duty at any real load, yes. Induction-hardened flanks resist the wear that opens the tooth form and lets the chain ride higher, which is the beginning of the end for a chain drive.

Can you supply the chain as well? Yes, simplex, duplex and multiplex in A and B series, matched to the sprocket.

What runout can you hold between bore and teeth? It is specified per drawing; what matters is that it is stated. Runout is what decides whether the chain loads evenly across its width.

Related pages

• Gear racks
• Spur and helical gears
• CNC machined parts