This standard applies to commonly used cross-recessed machine screws made of filter steel (hereinafter referred to as steel machine screws), stainless steel cross-recessed machine screws (hereinafter referred to as stainless steel machine screws), and cross-recessed machine screws made of non-ferrous metals. This specifies machine screws with screws (hereinafter referred to as non-ferrous metal machine screws). Remarks 1. When steel machine screws, stainless steel machine screws, and nonferrous metal machine screws are collectively referred to, they are simply called machine screws. 2. Machine screws not specified in the main body of this standard are specified in the annex. 3. Reference standards for this standard are shown in Attached Table 5. 4. The corresponding international standards of this standard are shown in Appendix 6.