ISO 1479 vs GB/T 5285

Hex Head Tapping Screw

Interchangeable: Yes. Every dimension is the same, in all 9 sizes. Order either.
Which to order: The number on your drawing. We make both: ISO 1479 and GB/T 5285.
GB/T 5285: China's version of ISO 1479, with the same dimensions.
Sizes: ST2.2 to ST9.5 in both.

Size by size

Size	PThread Pitch		aThread Runout		sWrench size		sWidth Across Flats		eAcross corners		kNominal Head Height		kHead Height		rRadius		yPoint Length — C (ref.)		yPoint Length — F (ref.)		yPoint Length — R (ref.)
Size	ISO 1479	GB/T 5285	ISO 1479	GB/T 5285	ISO 1479	GB/T 5285	ISO 1479	GB/T 5285	ISO 1479	GB/T 5285	ISO 1479	GB/T 5285	ISO 1479	GB/T 5285	ISO 1479	GB/T 5285	ISO 1479	GB/T 5285	ISO 1479	GB/T 5285	ISO 1479	GB/T 5285
ST2.2	0.8same		0.8same		3.2same		3.02same		3.38same		1.6same		1.3same		0.1same		2same		1.6same		–	–
ST2.9	1.1same		1.1same		5same		4.82same		5.4same		2.3same		2same		0.1same		2.6same		2.1same		–	–
ST3.5	1.3same		1.3same		5.5same		5.32same		5.96same		2.6same		2.3same		0.1same		3.2same		2.5same		2.7same
ST4.2	1.4same		1.4same		7same		6.78same		7.59same		3same		2.6same		0.2same		3.7same		2.8same		3.2same
ST4.8	1.6same		1.6same		8same		7.78same		8.71same		3.8same		3.3same		0.2same		4.3same		3.2same		3.6same
ST5.5	1.8same		1.8same		8same		7.78same		8.71same		4.1same		3.6same		0.25same		5same		3.6same		4.3same
ST6.3	1.8same		1.8same		10same		9.78same		10.95same		4.7same		4.1same		0.25same		6same		3.6same		5same
ST8	2.1same		2.1same		13same		12.73same		14.26same		6same		5.2same		0.4same		7.5same		4.2same		6.3same
ST9.5	2.1same		2.1same		16same		15.73same		17.62same		7.5same		6.5same		0.4same		8same		4.2same		–	–