The 8.8-grade DIN7991 countersunk head socket head cap screws are classified according to the hardness of the screw wire, tensile force, yield strength, etc. Different product materials must have different grades of hexagon socket head cap bolts corresponding to them. All hexagon socket head cap screws have the following grades:

Hexagon socket head cap screws are divided into ordinary and high-strength according to the strength of the grade. Ordinary socket head cap screws refer to grade 4.8, and high-strength socket head cap screws refer to grades 8.8 and above, including grades 10.9 and 12.9. Grade 12.9 socket head cap screws generally refer to knurled, natural black hexagon socket head cap screws with oil.

The performance grades of hexagon socket head cap bolts for steel structure connection are divided into more than 10 grades such as 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9, etc. The bolts of grade 8.8 and above are made of low-carbon alloy steel or medium-carbon steel. After heat treatment (quenching and tempering), they are generally called high-strength bolts, and the rest are generally called ordinary bolts. The bolt performance grade label consists of two parts of numbers, which represent the nominal tensile strength value and yield ratio of the bolt material.

Prince Fastener  focus on product categories:

Hexagon bolts GB5782 DIN931 (ISO4014), GB5783 DIN933 (ISO4017), DIN609 (refined screws)

Hexagon socket head bolt GB70 DIN912 (ISO4762), DIN7984, DIN6912, ISO7380, DIN910, ISO7379,

Flat pad GB97, DIN125, DIN433, DIN1440, DIN6916, DIN7989A, DIN9021,

Spring washer DIN127,DIN128,

Lock washer NORD LOCK lock washer, double-sided tooth washer, outer (inner) serrated lock washer (DIN6798), outer (inner) tooth lock washer (DIN6797), wave washer DIN137, dishwasher DIN2093, DIN6796, T Shaped bolts DIN186, eye bolts DIN580, carriage bolts GB12.GB14.DIN603,

Locating pins DIN94, DIN1473, DIN6325, DIN7979,

Set screws DIN913, DIN914, DIN915, DIN916, DIN906, DIN908, Phillips screws DIN7985, DIN965, slotted screws DIN84, slotted screws DIN7997-Z (NEN2253), DIN7995-Z, Phillips screws,

Threaded bar DIN975, DIN976, stud DIN939(NEN2332), DIN938(NEN2331), with flange bolt DIN6900, ISO7380, DIN6921, with flange locking bolt, fisheye bolt DIN444,

Hexagon Nut DIN934 (ISO4032), Hexagon Thin Nut DIN439, Cap DIN1587, DIN917, Nylon Self-Locking Nut DIN982, DIN985, Square Nut DIN562, DIN557, Snap Nut DIN7967, Round Nut DIN1804W, Weld Nut DIN928 (Square Weld Nut), DIN9299 (Hexagon Weld Nut), Flange Nut DIN6923,

Product standard: German standard DIN, international standard ISO, American standard ANSI, British standard BS, European standard EN, Dutch standard NEN, French standard NF, national standard GB … Product material: stainless steel 304.316.316L.310S.25/20. B8.B8M.904.904L.A2.A4.A2-70.A4-70.A4-80…

Carbon steel materials include: 20#.35K.45# steel, 30CrMo.35CrMo.40CrMo.42CrMo.SMC435.42CrMoA, etc. 4.8, 8.8, 10.9, 12.9;

Other materials are copper screws, aluminum screws, titanium alloy screws, nylon, plastic, polyether ether ketone, PTFE polytetrafluoroethylene, etc.

Surface treatment: Product surface treatment includes: environmental protection (RoHS) galvanized, colorful, blue and white, copper, tin, spacer, Teflon, Dacromet, chrome, silver, bronze, imitation gold, nickel plating, black plating, dark green plating, typical blackening, high blackening, etc.; Hexagon socket head cap bolts, hex head cap bolts, fine thread bolts, and other products.