SIZE REFERENCE / YZEFY SPROCKETS
12A sprockets
12A sprockets are selected for industrial power transmission, conveyors, material handling and international OEM machinery. The 12A designation identifies the ISO 606 A-series chain family, but it does not finish the sprocket specification. Confirm strand, teeth, bore, keyway, hub and available axial space before ordering. 12A chain identification starts with the A-series suffix, then moves to teeth, strand, bore and hub details for the actual sprocket.
A standard request can start with the chain marking and required tooth count. A custom or replacement request should include the applicable drawing, sample, measured sprocket or shaft information. The chain and the shaft interface need to be checked as one assembly.
Size reference
12A Sprockets
- SpecificationReference
- Chain referenceISO 606 12A
- SeriesA-series
Quick Specifications
| Specification | Reference |
|---|---|
| Chain reference | ISO 606 12A |
| Series | A-series |
| Pitch | 19.050 mm |
| Roller or bush diameter | 11.910 mm |
| Inner width | 12.570 mm |
| Strand | Simplex, duplex or triplex, stated in the complete chain designation |
| Sprocket forms | Type A plate, Type B hub, Type C double hub and drawing-defined forms |
| Bore and hub | Pilot or finished bore, keyway, bushing or custom shaft interface |
Chain & Size Reference
These values identify the mating chain. They are not finished sprocket dimensions. Pitch diameter, outside diameter, tooth width, bore and hub dimensions depend on the tooth count, strand arrangement and machine drawing.
| Chain | Series | Pitch (mm) | Roller or bush diameter (mm) | Inner width (mm) |
|---|---|---|---|---|
| 12A | A | 19.050 | 11.910 | 12.570 |
Simplex / Duplex / Triplex
A simplex sprocket carries one chain row. Duplex and triplex versions carry two or three rows and use different transverse spacing and total tooth width. Include the full strand suffix with 12A. The base designation alone is not enough for a multi-strand part.
Available Sprocket Configurations
- Type A plate sprockets for compact layouts or separate-hub assemblies.
- Type B sprockets with a hub on one side.
- Type C sprockets with hubs on both sides or a wider shaft interface.
- Idler, split, weld-on, bushing-mounted and other drawing-defined forms.
Do not assign a tooth count from the chain size alone. Confirm driver and driven teeth in the RFQ or drawing.
Materials
Carbon steel is used for many general industrial drives. Alloy steel can be considered for higher load, shock or wear requirements. Stainless steel suits corrosion, washdown and cleaning exposure. Cast iron, aluminum and engineering plastics may fit specific low-load or weight-sensitive designs. State the material grade, supply condition and certificate requirement in the RFQ.
Heat Treatment & Surface Treatment
Tooth hardening, induction hardening or carburizing may be specified when the drawing or application requires greater tooth wear resistance. Protective surface treatment can be considered for corrosion, storage or washdown conditions. Include hardness, case depth, treated area, surface finish and inspection method when those values are controlled by the purchase specification.
Custom 12A Sprockets
Send the ISO series, chain reference, number of teeth, strand, bore, keyway, hub dimensions and quantity. Add material, heat treatment, surface treatment, tolerances, marking and inspection requirements from the drawing. For sample-based work, include the chain marking, tooth count, pitch, roller or bush diameter, inner width, face width and shaft measurements. Application speed, load, center distance and operating environment can resolve details that a worn sample cannot show.
Replacement Sprockets
A replacement 12A sprocket should be checked against the mating chain and shaft, not copied from worn tooth tips. Send the old chain marking, tooth count, bore, keyway, hub, face width, photos and any part number. If the failure involved chain elongation, poor alignment, inadequate lubrication or contamination, inspect the chain and mating sprocket before replacing one part.
Applications
12A sprocket requests commonly come from industrial power transmission, conveyors, material handling and international OEM machinery. The application helps define the review, but it does not choose the tooth count or shaft connection. Load, speed, chain line, environment and mounting space still belong in the specification.
Standard & Compatibility Notes
ISO 12A and 12B share a 19.050 mm pitch in the reference tables but do not share the same chain dimensions or sprocket selection. The series suffix must stay in every RFQ and drawing. Compare pitch, roller or bush diameter, inner width, strand spacing, tooth form and shaft interface before approving a substitute.
How to Select
- Confirm ISO 606, the A-series suffix and the complete 12A chain reference.
- State simplex, duplex or triplex and the complete strand suffix.
- Record driver and driven teeth, speed ratio, center distance and chain line.
- Check pitch, roller or bush diameter, inner width and transverse spacing.
- Select Type A, Type B, Type C or another drawing-defined form.
- Specify bore, keyway, locking method, hub dimensions and axial clearance.
- Add material, treatment, finish, quantity, inspection and drawing revision.
- Send a sample or measured photo if any original dimension is uncertain.
FAQ
What are the 12A dimensions?
The 12A row lists a 19.050 mm pitch, 11.910 mm roller or bush diameter and 12.570 mm inner width.
Does 12A specify simplex, duplex or triplex?
No. State the complete strand arrangement because row spacing and tooth width change with the strand count.
What is needed for a 12A replacement?
Send the mating chain, teeth, bore, keyway, hub, face width and shaft measurements.
Can 12A sprockets be made from a drawing?
Yes. Include the drawing revision and the material, treatment and inspection requirements.
Request a Quote for 12A Sprockets
Send the ISO series, chain reference, number of teeth, strand, bore, keyway, hub, quantity and application. For custom or replacement work, attach the drawing, sample photo, old sprocket dimensions or existing part number. This prevents a shared-pitch comparison from being treated as a complete fit confirmation.