Screw Thread Tolerances Profiles Roymech

Screw Thread Tolerances Profiles Roymech D 2 tolerance grades 4,5,6,7 & 8. d 2 tolerance grades 3,4,5,6,8 & 9. the tolerance positions available are ei = g & h for female threads and es = e,f g, or h for male threads. selection of tolerance classes. to simplify the selection of the tolerance classes threads have been divide into three categories. Relevant standards bs 5346:1976 specification for iso metric trapezoidal screw threads iso 2901:1977 iso metric trapezoidal screw threads basic profile and maximum material profiles iso 2902:1977 iso metric trapezoidal screw threads general plan iso 2903:1977 iso metric trapezoidal screw threads tolerances iso 2904:1977 iso metric trapezoidal screw threads basic dimensions din 103.

Screw Thread Tolerances Profiles Roymech 56 Off M56 x5,5. m60 x 5,5. m64 x 6. m68 x 6. iso thread dim 1,6mm to 600mm dia. notes: the dimensions identified are for medium tolerance grade 6h 6g for the screw threads. this grade is implied if it is not designated with the screw size e.g m20 x 2. ** bs 3643 and iso 965 simply indicate that the contour of the major dia of the female thread should. The thread form is in accordance with bs 3643:2007. all dimensions in millimetres. relevant standards. bs 3643 part 1:2007 iso metric screw threads. principles and basic data. bs 3643 part 2:2007 iso metric screw threads. specification for selected limits of size. bs 3692:2001 iso metric precision hexagon bolts, screws and nuts. The following formula for the tensile stress area of the (male) screw. this is based on iso 898 part 1. see calculation below d p = pitch circle diameter of thread. dp = (d 0.64952.p ) the thread shear area = a ss. when the female and male threads are the same material. ass = 0.5. π. dp. le = 0.5 π (d 0.64952.p ). Screws a note on tapping holes. i normally specify a tapped hole depth of 1.5 dia for a fully threaded hole in a blind tapped hole (steel male and female). the depth of threaded hole if a plug tap is not used i.e for automatic one stage tapping would be deeper.