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