galvanized m4 self tapping screws

galvanized m4 self tapping screws

Descriptions of m4 screw:

  Self-tapping screw is a kind of fastener with thread that can tapping drill the required negative thread on the prebored holes of metal or non-metallic material. While connecting, firstly make the bottom hole of the thread on the connected elements and then screw the self-tapping screw into the bottom holes of the thread. Because the surface of self-tapping screw has high hardness (≥45HRC), it can tap and drill internal thread in the bottom holes of the connected elements and then connect them.

Suitable standards

Characteristics of m4 screw:

1.This self-tapping screw can automatically mold or tap out its matched thread so that it has high locking ability in combinations and it can be assembled and disassembled. Its combination with small bolts together with its dimension, thread style, head type and tapping and drilling performances make it suitable for almost all kinds of engineering applications.

2.The general self-tapping screw is screws with self-tapping pitch thread and self-tapping effects. It needs not to be matched with the nuts. There are many head types of this kind of screw, such as outside hexagon head, hexagon socket head, bank head, countersunk head, and umbrella head. Its cuspidal end is the main part that plays the self-tapping role.

3.Non-metallic or soft metal material need no low hole and tapping thread while using this kind of screw. The pointed end plays the self-tapping role while normal screw has flat end and consistent thickness.

4.The holes made by this kind of screw need no tapping tooth and the screw has pointed end with large tooth pitch. Metal and plastic always use this kind of screw for connecting and fixing. Self-tapping screw can tap, drill, crush and press the corresponding thread on the consolidated of materials relying on its own thread.

5.Self-tapping screw is also called self-tapping bolt and they all have self-tapping effects. The main advantage of self-tapping screw is that it needs not to be matched with nuts and this will help to save enormous nut costs.

6.The head of screw has round, flat, half-countersunk and countersunk 4 main types. It is generally made of carburizing steel and after thermal treatment, the surface hardness of carburizing steel will not lower than 45HRC.

7.Compared with the thread of normal screw with the same out diameter, the larger the screw pitch, the smaller the inner diameter and this rule is standardized.

8.The material of self-tapping screw has carbon and stainless steel two kinds. Carbon steel material is usually 1022 and it is widely used by doors, widows, and iron sheets. Its head is a bearing surface with enlarged area.

Manufacture Process of m4 screw:

Heading → washer → assembly → Threading →  Secondary machine →heat treatment → plating → Anti-slipping →   Baking→ QA Package → Shipping

Our advantages:

1.Non-standard/standard/OEM/ODM/customized service provided

2.high precision

3.Small MOQ available

4.Fast lead time

5.ISO9001:2008 Certified

Detail Quantity Inspection:

A. 100% inspection during the Production

B. QC department

C. ISO9001,ISO14001,ROHS

D. Inspection equipment: 

     Hardness test, torque test meter, salt spray endurance test, mechanical sizes test, 

     Hydrogen embrittlements test, ROHS report Mill test certification and etc as per your need.

Other products:

 1.Packaging : inner packing is PP bag/ small box ,outside is carton packing.

 2.Shipping : Sea transportation and air transportation or by express delivery.

 3.Payment : T/T, L/C ,D/A,D/P ,also as your request.

1. Good hardness

2. High and low temperature resistant

3. Multicolor choose

4. Competitive Price

5. Superior Quality, TUV CERT ISO9001:2000 quality assurance

6. Artificial stone without any radiation

7. Punctual Delivery 

8. Supply wooden pallet

9. Meet different market’s need: America, Europe, Asia, and so on.