A screw is only equipped with one spring washer or only one flat washer, or a combination screw with only one flower tooth. A screw with a spring washer and a flat washer, usually called a three-piece screw. The combination screw country number is indicated by GB9074. Commonly used cross recessed small pan head three combination screws country number is GB9074.8. This .8 refers to the small head. Also known as the pan head screw
A screw is only equipped with one spring washer or only one flat washer, or a combination screw with only one flower tooth. A screw with a spring washer and a flat washer, usually called a three-piece screw. The combination screw country number is indicated by GB9074. Commonly used cross recessed small pan head three combination screws country number is GB9074.8. This .8 refers to the small head. Also known as the pan head screw head size. Expressed as PM with letters. Professional combination
Screw manufacturers, customary representation method is triple-PM. The commonly used cross recessed pan head combination screw country number is GB9074.4. Professional combination of screws called big pan head. Or R head, or B head. In other words, the head of this combination screw is larger than the head of the small pan head combination screw and must be thicker. There is also a commonly used combination of external hexagon screws, this is
Cross hex screw combination. Often referred to as a hex socket combination screw. The country code is GB9074.13
Combination screw material is divided into iron and stainless steel. Iron is made of different iron screw wire. General combination screw wire is used 1010,1018,10B21 and so on. 10B21 is used to make 8.8 combination screws. Like 8.8 grade hex screws, do 10B21 wire to do. After doing a good job, go to heat treatment. After heat treatment, remove hydrogen
After plating. This is to prevent the spring washer of the hexagon socket combination screw from breaking. Stainless steel combination screws, combination screws market, generally refers to stainless steel SUS304 combination screws. 201 combination screws generally do very little. Few manufacturers go to produce the 201 combination screws. Because the hardness of the stainless steel 201 screw wire is not well controlled, it is easy to produce cracks.