Flat Phillips Step Screws

Overall Description

Flat Phillips Step Screws Details

Flat Phillips Step Screws Application

Flat Phillips Step Screws Production Flow

The final cold temperature of the screw fastener surface is also one of the important reasons for the cracking of the screw fastener. It has been proved that the general quenching crack occurs in the low temperature stage of the late cooling stage. At this time, the screw fastener has no plasticity and the stress cannot be caused.

For the relaxation of plastic deformation, for some large-section workpieces, due to the fear of impermeability, the cooling time in the cooling medium is too long. This method is undoubtedly prone to cracking.

When the chemical composition of steel is constant, the most intense cooling medium is used. It is also difficult to maintain the stability of austenite in a certain cross-section attempt, without precipitation of ferrite and no pearlite transformation, that is, lowering the final cooling temperature, and not improving the overall mechanical properties of the screw fastener, but increasing the quenching cracking.

For the medium-carbon alloy steel, the final cooling temperature should not be controlled below 250 °C, and the cooling time should not be too long.

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FAQ:

How is the salt spray test of steel step screws?

We use 5% sodium chloride solution with a little glacial acetic acid. The solution will down to about 3, so it will be acidic. At a result, the salt spray will be acidic as well. The rate of corrosion is 3 times faster than NSS test.

But different test for different material. We will choose the good way for evaluation.

What is your term of payment for zinc plating machine screws?

We can accept West Union, Money Gram, and T/T.

What's your production time of custom machine screws?

It's depends on your quantity and the complexity of the products. Normally we cost 2-4 weeks.