D12B21

Metric Roller Chain Sprocket

Item #100965872

20 mm Minimum Bore

70 mm Maximum Bore

+ Show More

Auto Replenish

each One-time purchase

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.

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

Specifications

Martin No.	12B21
Family Name	No. 12 - 19.050 mm Pitch - Double - Type B & C
Hardened Teeth	Without Hardened Teeth
Inch/Metric	Metric
Sprocket Style	B
Material	Steel
Pin Diameter	12.065 mm
Caliper Diameter	115.39 mm
Series	B
Outside Dia. [Min]	139.56 mm
Single Strand Tooth Thickness	10.87 mm
Root Diameter	115.8 mm
Pitch Diameter	127.8 mm
Width Across Teeth	30.33 mm
Bore Type	Reborable
No. of Strands Across	2
Bore Range [Min]	20 mm
Chain No.	12B, 12B-2
No. of Teeth	21
Chain Pitch	19.05 mm
Length Through Bore	50.01 mm
Hub Length Thru	39.13 mm
Hub Dia.	100 mm
Bore Style	Minimum Bore
Pitch Root Diameter	115.8 mm
Outside Dia.	139.56 mm
Pitch Diameter [Min]	127.8 mm
Bore Range [Max]	70 mm
Weight	9.07 LB
EAN or UPC	697950401416