SIZE REFERENCE / YZEFY SPROCKETS
04A sprockets
04A sprockets are selected for compact international machinery, small conveyors, packaging and indexing equipment. The 04A 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. The 04A chain has a small pitch, so the finished sprocket still needs a confirmed tooth count and shaft interface before a drawing is released.
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
04A Sprockets
- SpecificationReference
- Chain referenceISO 606 04A
- SeriesA-series
Quick Specifications
| Specification | Reference |
|---|---|
| Chain reference | ISO 606 04A |
| Series | A-series |
| Pitch | 6.350 mm |
| Roller or bush diameter | 3.300 mm |
| Inner width | 3.180 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) |
|---|---|---|---|---|
| 04A | A | 6.350 | 3.300 | 3.180 |
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 04A. 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 04A 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 04A 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
04A sprocket requests commonly come from compact international machinery, small conveyors, packaging and indexing equipment. 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 606 A-series references are derived from ANSI practice, but an A-series designation should still be checked against the complete chain dimensions and drawing. 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 04A 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 04A sprockets?
04A sprockets are selected for ISO 606 A-series chain reference 04A. Teeth, strand, bore and hub are separate purchase fields.
What are the 04A chain dimensions?
The reference row lists a 6.350 mm pitch, 3.300 mm roller or bush diameter and 3.180 mm inner width.
Can 04A and 04B sprockets be substituted?
No. Their pitch and chain dimensions differ. Compare the complete chain reference before selecting a substitute.
What should an 04A RFQ include?
Send the chain reference, teeth, strand, bore, keyway, hub, quantity, application and any drawing or sample.
Request a Quote for 04A 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.