Gr 8, SAE J429 Mechanical and Mate✘φrial Requirements for Ext≠ ↔☆ernally Threaded Fasteners

Grade 8, hex head bolt, grad ↑e 8 bolt, fasteners, machine♦£λ bolt, A manufacturing Grade 8 sc♦ε↔​rews and bolts by hot forging or m→φachining from bar.

Designation:

Grades are designated b∏Ω≈•y numbers where increasing numbers ©♥≤represent increasing tensile strength&♠ and by decimals of whol↔π§$e numbers where decimals represent variΩ≤ations at the same str×±ength level.

Bolts and screws are normally av>"<✘ailable in Grades 1, 2, 5, 5.2, 8, 8.≈ &✔2

Studs are normally available in Gr★∏ ades 1, 2, 4, 5, 8, 8.1

Chemical composition:

All fasteners shall be  →made of steel conformingβ¥₹ to the chemical composition requireme©ε£nts in Table 2

Refer to SAE J403, J404, J1268 for c♥"hemical composition limits •→§×of standard steel grades. Other st₩←∞andard and non-standard steels not defi÷£₽ned by the above standard are acce±σ¥¶ptable if the resultant fas ↔teners comply with all of the requi¥✘©rements in this standard. For γ←grades 5, 5.1, 5.2, 8, 8.1, 8.2 the max∏'imum content of bismuth"€γ selenium, tellurium, or lead each s↔→₩♣hall be 0.02%.

Crystallization:

Alloy and medium carbon ∏"₹ steels with additive boron f ™≈≈or manufacturing Grades 8 and 8.2 faste☆Ω₹₽ners shall be fine gra​€‌φined steel.

Heading practice/ head fo¶'₩<rming: Hot forged

Threading practice/ th₹₽read forming: roll threaded

Coating: natural+oil, black, dac ☆σromet, zinc-plate, HDG, ​δε<geomet, dorken

Machanical requirementd fσ₽₹or Gr-8 bolts, screws, studs and U bol®÷≤¶ts