Special screws-general representation of screws


General representation of screws Example: 4 X 10 PW A H […]

General representation of screws

Example: 4 X 10 PW A H C (+)
① ② ③ ④ ⑤ ⑥ ⑦

① Screw diameter

② Screw length

③ Screw head type
B: Spherical cylinder head; C: Cylinder head; F(K): Countersunk head; H: Hexagon head; HW: Hexagon head with washer; O: Half countersunk head; P: Flat head; R: Half head
; PW: flat head with washer; T: big flat head; V: mushroom head;

④ Screw thread type
A: Self-tapping pointed tail (the first type of Japanese standard) sparse AB: self-tapping pointed tail (type 4 of the Japanese standard) dense
B: Self-tapping flat tail (the second type of the Japanese standard) sparse C: Self-tapping flat tail (the third type of the Japanese standard) dense P: double wire teeth HL: high and low teeth U: pineapple teeth
T: Self-tapping flat-tail cutting feet AT: Self-tapping threaded tip-tail cutting feet M: Mechanical teeth
BTT: B-shaped triangular teeth CCT: C-shaped triangular teeth PTT: P-shaped triangular teeth STT: S-shaped triangular teeth

⑤ Heat treatment
H: With heat treatment N: Without heat treatment

⑥ Surface treatment
Zn: White zinc C: Color zinc B: Blue zinc F: Black zinc O: Black oxide Ni: Nickel Cu: Bronze Br: Red copper P: Phosphating

⑦ Remarks
(+): Cross slot (-): Single slot (T): Chrysanthemum slot (H): Hexagon socket
(PZ): Pozi-shaped groove (+-): +- groove (Y): Y-shaped groove (H): H-shaped groove
(L): Anti-retracting tooth (WIS): Single movable spring washer (WIF): Single movable flat washer
(WIT): Single movable external tooth washer (W2SF): Double movable flat spring washer
(W=6mm): The outer diameter of the washer is equal to 6mm.      (SUS): Stainless steel (Cu): Brass
(Br): Copper (8.8): Grade 8.8 screw (10.9): Grade 10.9 screw
(12.9): 12.9 grade screw (R): other notes