Service HotlineThe marking format of the thread mark is: Thread code - thread tolerance zone code (pitch diameter, top diameter) - screw length l) Tolerance zone code is represented by numbers plus letters (inner thread with uppercase letters, external thread with lowercase letters) , such as 7H, 6g, etc., it should be specially pointed out that 7H, 6g, etc. represent thread tolerance, while H7, g6 represent cylinder tolerance code. 2) The length of rotation is specified as short (represented by S), medium (represented by N), and long (represented by L). In general, the thread engagement length is not marked, and the thread tolerance zone is determined by the medium engagement length (N). If necessary, add the screw length code S or L, such as M20-5g6g-L. When special needs are required, the value of the screwing length can be indicated, such as M20-5g6g-30.
Yueluo's thin plate rivet method, the thickness of the metal thin plate is less than 0.8mm. The convex rib extrudes the metal sheet adjacent to the rivet hole. The protruding rib is annular, and the protruding rib surrounds the rivet. The rivet head is provided with a positioning structure, the rivet head is provided with a positioning structure for docking the positioning structure, and the positioning structure and the positioning structure are mutually butted through the rivet to align the convex rib with the rivet
Cross recessed pan head screws refer to cross recessed machine wire screws, which are represented by the letters PM. The country stipulates that the thread specification is M1.6-M10, the performance level is 4.8, A-50, A2-70, CU2, CU3 and AL4, H-type and Z-type cross recessed, and the product grade is Class A cross recessed pan head screws . If other technical requirements are needed, they should be selected from the current standards (such as GB/T196, GB/T3106, GB/T3098.1, GB/T3098.6 and GB/T3098.10).
In the non-standard mechanical design, when the middle part of the long shaft or rod-shaped structure needs to be threaded, the end is limited and the nut cannot be penetrated, which will cause the problem that the installation cannot be realized. In order to solve this problem, it often has to be cancelled. It is not conducive to the realization of equipment cost reduction and optimal function, and even the problem cannot be solved, and another way out is needed.
(1) Galvanized (blue-white, multicolored, black) 1. Pretreatment: thermal degreasing tank (5 tanks) - electrolytic degreasing tank (3 tanks) - rust removal tank (4 tanks) 2. Electroplating: electroplating tank (20 tank) (ammonium chloride, zinc oxide, gloss, softener solution). 3. Post-treatment: Melting tank (1 tank) - Green medicine tank (1 tank) - (blue-white/multicolored/black) (2), blackening: 1. Pre-treatment: thermal degreasing tank (4 tanks) - rust removal Tank (4 tanks) 2. Blackening: blackening (5 tanks) (flake alkali, sodium nitrite solution) 3. Post-treatment: anti-rust oil (1 tank) (3), phosphating: 1. Pre-treatment: heat Degreasing tank (1 tank) - Derusting tank (1 tank) - Electrolytic degreasing tank (1 tank), - Surface treatment (1 tank) 2. Phosphating: Phosphating (forming a film) 3. Post-treatment: dipping in anti-rust oil (2 tanks) (4) Hot dip galvanizing: 1. Pretreatment: degreasing tank (1 tank) - rust removal tank (1 tank) - FLUX tank (1 tank) - drying 2. Hot dip galvanizing: hot Zinc immersion tank 3. Post-processing: centrifugal treatment - ammonia chloride cooling - water cooling
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: black galvanized cup head hexagon socket head bolts, flat head copper studs, copper studs, flat washers GB1228 and other products, we can provide you with products suitable for you fastener solutions.
