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How to specify a Machine Screw

What to put on an RFQ for Machine Screw: the ratings, documents, and constraints that change the quote.

25 Oct 2026 · 3 min read · Tradinor Desk

Specification points for Machine ScrewTRADINOR · FIGUREWhat to lock for Machine ScrewStrengthHead and driveCoatingQuantity and lot
Put these on the RFQ for Machine Screw before you compare prices.

A buyer searching for Machine Screw is usually trying to stop a bad substitute. A fastener or fitting is specified by size, material, strength, and the corrosion around it. The notes below are selection criteria for a Machine Screw. They are not a catalog promise. Confirm every rating on the current datasheet, drawing, or test report for the revision you will receive.

What has to be true of Machine Screw

A fastener or fitting is specified by size, material, strength, and the corrosion around it. For a Machine Screw, start from the duty, then the interface to the rest of the machine or the room, then the document that proves the claim. A lower price that leaves one of those blank is a different product.

Machine Screw is easy to confuse with Swivel Caster. If the quote could be read as either, add the line that separates them: the rating, the fitment, or the standard named below. Link the drawing number to that line so receiving inspection can reject the wrong one.

Numbers that change the quote

Line What to write for Machine Screw
Strength Property class or a stated tensile figure.
Head and drive Head style and the driver the line already uses.
Coating Zinc, galvanize, or another coat matched to the environment.
Quantity and lot Batch traceability if the assembly is safety related.
Size and thread Diameter, pitch, length, and the standard of the thread.
Material Steel grade, stainless alloy, or brass, not only the color.

How to compare two offers

Lay both quotes for Machine Screw on one sheet and line up strength, head and drive, and coating. If a cell is empty, the offer is not finished. Ask for the missing line in writing. When those match, the honest difference is lead time, the test evidence, and who carries the warranty. Do not average a fully specified Machine Screw with a cheaper line that omitted strength.

Documents worth having before the deposit

Ask for the material certificate when the joint is structural. The file should name Machine Screw and the revision, not only the supplier’s homepage. A factory quality certificate such as ISO 9001 can sit beside that file. It does not replace it.

Failures that show up after delivery

  • Choosing a coating that the chemical on site strips.
  • Leaving thread pitch off the order.
  • Substituting a similar head with a lower property class.

On a Machine Screw, the expensive version of the first mistake is discovering it after the goods are in the crate. Put the rejection condition in the purchase order while the supplier can still restate the offer.

A worked RFQ line

Use this shape, then replace the brackets with your duty: “Machine Screw — Write size, thread, material, property class, and coating.” That sentence is a template, not a rating of any brand. If a supplier’s datasheet uses different units, convert them onto this sheet so the next offer can be compared.

Where words like waterproof / IP65 belong

Searches often add a constraint to Machine Screw: waterproof / IP65, or IP67. Keep those on this page. IP65 in IEC 60529 means dust-tight and protected against water jets. Write that code if hoses are the real exposure. The word waterproof alone does not name a test. IP67 is dust-tight plus a defined temporary immersion. It is not a rating for living underwater, and it says nothing about sunlight or salt. If you need a third constraint, add it as another line on the same drawing. A second URL that only swaps the adjective does not give a buyer a second fact.

Related in this section: how to specify Swivel Caster.

Questions buyers actually ask

What should an RFQ for Machine Screw include?

Write size, thread, material, property class, and coating.

Is a cheaper Machine Screw the same part?

Only if strength, head and drive, and the documents match. A missing line is a different offer.

Do waterproof, OEM, or IP words need their own page?

No. For Machine Screw they are extra lines on this specification. Ask for the test or the drawing that gives the word a value.