A buyer searching for Caster 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 Caster. 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 Caster
A fastener or fitting is specified by size, material, strength, and the corrosion around it. For a Caster, 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.
Caster 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 Caster |
|---|---|
| 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. |
| Strength | Property class or a stated tensile figure. |
How to compare two offers
Lay both quotes for Caster on one sheet and line up head and drive, coating, and quantity and lot. 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 Caster with a cheaper line that omitted head and drive.
Documents worth having before the deposit
Ask for the material certificate when the joint is structural. The file should name Caster 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
- Substituting a similar head with a lower property class.
- Choosing a coating that the chemical on site strips.
- Leaving thread pitch off the order.
On a Caster, 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: “Caster — 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 OEM / custom belong
Searches often add a constraint to Caster: OEM / custom, or RoHS / CE. Keep those on this page. OEM or custom means a drawing, a revision, and a statement of who owns the tool. Without those, you are buying the catalog part. RoHS is a material limit. CE is a declaration that lists the rules relied on. Ask for the document that names this part number and revision. 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 Caster include?
Write size, thread, material, property class, and coating.
Is a cheaper Caster the same part?
Only if head and drive, coating, and the documents match. A missing line is a different offer.
Do waterproof, OEM, or IP words need their own page?
No. For Caster they are extra lines on this specification. Ask for the test or the drawing that gives the word a value.