Archery Spine Testers           Legal:Links on this page may  pay us a commission. Amazon Affiliate Program Member.
The Archery Trade Association standard for measuring arrow spine requires this test: Suspend a 1.94-pound weight at the shaft’s center, and use a machine to measure the deflection or bend at that point.
Deflection is measured in inches. Some typical deflection measurements are .500, .400 and .350. These measurements correspond to the spine sizes most manufacturers use to mark arrows.
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DIY Spine Testers
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Machinist Dial
Brackets
1/4" x 1" bolt, nut and washers for mounting dial indictor
3/4" long screws for  mounting corner brackets.  Pan head is my preference?
Screw Hook #10
Scuba Weight 2#
can drill holes to meet ata standards ~1.94 lbs.
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