Type - DIN938. DO NOT include the small threaded end (for M8 studs this is + 8mm). M8 x 35 = 20mm + 15mm. M8 x 40 = 20mm + 20mm. M8 x 45 = 20mm + 25mm. M8 x 50 = 20mm + 30mm. M8 x 55 = 25mm + 30mm.
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