Standard DIN 439. M4 - 4mm (Suitable Spanner Size 7mm). M8 - 8mm (Suitable Spanner Size 13mm). M10 - 10mm (Suitable Spanner Size 17mm). M12 - 12mm (Suitable Spanner Size 19mm). Cake Toppers. Locking Nuts are designed to lock in place whilst installing.
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