28A21

Metric Roller Chain Sprocket

Item #100967154

40.03 mm Minimum Bore

255.58 mm Maximum Bore

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Product Details

Maximum bores shown will accommodate standard keyseat and setscrew over keyseat. Slightly larger bores are possible with no keyseat, shallow keyseat, or setscrew at an angle to keyseat.

Chain rows are parallel and precisely spaced to increase longevity of sprocket and chain
Manufactured of high carbon steel
Precise machining and processes ensure consistent finish and high quality
Bores are concentric to pitch line, minimizing run out

Specifications

No. of Strands Across	1
Bore Style	Minimum Bore
Pin Diameter	27.94 mm
Series	A
Length Through Bore	29.44 mm
No. of Teeth	21
Hub Projection	N/A
Bore Range [Max]	255.58 mm
Single Strand Tooth Thickness	29.44 mm
Chain Pitch	44.45 mm
Outside Dia. [Min]	325.86 mm
Root Diameter	270.3 mm
Sprocket Style	A
Inch/Metric	Metric
Hardened Teeth	Without Hardened Teeth
Pitch Diameter [Min]	298.2 mm
Hub Dia.	N/A
Martin No.	28A21
Caliper Diameter	269.46 mm
Chain No.	28B, 28B-1
Bore Type	Reborable
Pitch Diameter	298.2 mm
Outside Dia.	325.86 mm
Width Across Teeth	29.44 mm
Hub Length Thru	N/A
Pitch Root Diameter	270.3 mm
Material	Steel
Family Name	No. 28 - 44.450 mm Pitch - Single - A
Bore Range [Min]	40.03 mm
Weight	25.99 LB
EAN or UPC	697950406732