ISO MINIATURE SCREW THREADS
This ISO Recommendation specifies ISO miniature screw threads with thread sizes from 0.3 to 1.4 mm diameter.
For technological and functional reasons the tolerancing system for these threads differs from the tolerancing system for ISO general purpose metric screw threads.

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Countersunk flat head screws (common head style) with type H or type Z cross recess — Product grade A — Part 1: Steel screws of property class 4.8
Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High Pressure or High Temperature Service, or Both
COATING, OXIDE, BLACK, FOR FERROUS METALS
Three wires for screw thread measuring and four wires for screw thread measuring
Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process
METRIC HEAVY HEX FLANGE SCREWS