N321-4 DIN 13 DIN 371 Material groups CHARACTERISTICS Technical drawing Profile sketch Tool data ID D1 Ø d1 Tol P l1 l2 d2 a 101553 M2.5 2.50 6H 0.450 50.0 10.0 2.80 2.1 3 2.05 Product range N321-4 M2.5 6H ID D1 Ø d1 Tol P l1 l2 l3 d2 a 101553 M2.5 2.50 6H 0.450 50.0 10.0 0 2.80 2.1 3 2.05 101555 M3 3.00 6H 0.500 56.0 12.0 18 3.50 2.7 3 2.50 101557 M4 4.00 6H 0.700 63.0 14.0 21 4.50 3.4 3 3.30