Q:What is the meaning of the screw and the 4 and 8?

He means that the tensile strength of the screw minimum 400MPa, the minimum yield strength of 320MPa (tensile strength of 80%). Please refer to the national standard GB3098.1 or ISO international standard ISO898-1 the requirements.

Q:Screw hole slip wire how to do?

With a small amount of 502 glue into the screw hole, and then screw into the screw, such as glue after solidification and then use the tip of the nose to pull the screw out (only the screwdriver is not afraid of causing the screw teeth), waiting for the glue to fully hardened

Q:Also known as screw nails, I want to nail on the board, but there is no way to nail into the hard, how nail?

You say is a self-attack nail with a screwdriver twisted into the picture is not self-tapping is not used on the board, which is used on the expansion tube, to change the nail or wood screws, or direct use Nail nail

Q:Why the screw thread more closely, spin into the more effort?

This is due to the spiral angle of the thread becomes smaller, the pitch of the thread, the lead becomes smaller.

Q:Why are the screws of the screw?

Fine thread thread pitch is small, the angle is small, self-locking is better, high strength, because the teeth are not wearable, easy to slip. Fine thread is often used in fine parts, thin-walled pipe fittings or by the impact, vibration and variable load connection, can also be used as fine-tuning mechanism for adjusting the thread.

Q:Want to fix something, which is a triple iron (do not know how thick), would like to ask what screws can be turned into? Can ordinary drill go in? The question is to consider the drill or consider the screw, or have to consider? Thank you! The

Because this screw (metal self-tapping screw) than iron, can eat iron. Coupled with its special design type, so it can be drilled less than its small diameter in the hole. So you have to first drill with a drill before drilling a hole smaller than its diameter it is possible to drill into.

Q:I would like to know the specifications of the two types of screws models, including length, diameter, diameter and pitch, etc.

M3: pitch: 0.5; diameter: 2.675; diameter: 2.459; outer diameter: 3; length: 6,8,10,12,16,18,20,25,30 (GB5783-86 specified length specifications) M6: Pitch: 1; diameter: 5.350; trail: 4.917; outer diameter: 6; length: 6,8,10,12,16,18,20,25,30,35,40,60. (GB5783-86 specified length specifications)

Q:What is the invention of the screw?

Should be the 18th century Mozzley in London invented all-metal precision screw lathe. The following year, Wilkinson made a nut and bolt making machine in the United States. Both machines can produce universal nuts and bolts. Nuts and bolts can be connected together metal parts, so to the 19th century, the manufacture of machinery to build houses of wood, has been replaced by metal.

Q:Screws are not slopes.

Can not simply say whether it is a specific analysis of specific issues

Q:Why should the screw twist clockwise?

Because the screw on the original flute is the clockwise direction of it