Standard Abrasives 701758, A/O Straight Cartridge Roll, 5/16 in x 1-1/2 in x 1/8 in 120, 7100093000 
Insize 4168-8E, STEEL STANDARD BALLS, 5/16″, 6940561981469
$13.67
To measure angle and diameter of taper holes
Material: tool steel
Hardness: HRC63
Diameter accuracy:?.00012?
Roundness .00004″
Supplied with manufacturer inspection certificate.
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