What is coarse pitch? (short answer)
Coarse pitch is the default metric thread pitch for a given diameter—the spacing catalogs assume when a drawing only says “M8” or “M10” with no pitch callout.
Example: M8 coarse ≈ 1.25 mm. M8 fine might be 1.0 mm. Same diameter, different geometry—they will not mate.
Full chart: Metric coarse vs fine thread pitch.
Why this search matters
Buyers type “what is coarse pitch”, “coarse pitch”, or “coarse vs fine” because ordering the wrong pitch is a common RFQ failure—the “M” size looks right, assembly fails.
Quick coarse defaults
| Size | Typical coarse pitch |
|---|---|
| M3 | 0.5 |
| M4 | 0.7 |
| M5 | 0.8 |
| M6 | 1.0 |
| M8 | 1.25 |
| M10 | 1.5 |
| M12 | 1.75 |
No fine callout on the print → start with coarse, then confirm before the PO.
Shop coarse-pitch 304 / A2-70
Most published SKUs are standard coarse unless marked fine:
| Need | Go here |
|---|---|
| Socket head (SHCS) | Socket head cap screws |
| Hex head | Hex head screws |
| Nuts | Hex nuts |
| Washers | Flat · Spring |
Partial vs full hex thread? ISO 4014 vs 4017.
RFQ line (copy/paste)
Metric · [Thread] · coarse (or fine + pitch) · [Length] · [Head] · A2-70/304 · [Standard] · qty
Example:
Metric SHCS · M8 · coarse 1.25 · 20 mm · hex socket · A2-70 / 304 · ISO 4762 · 500 pcs
→ sales@pisenfasten.com or Contact
Buying metric 304 / A2-70 by carton for a store or workshop? Review the quote-specific Wholesale terms; packaging, freight scope, documents, and lead time are confirmed in writing.
FAQ
Q: Is coarse pitch the same as UNC?
A: No. UNC is inch; here coarse means metric ISO default pitch.
Q: When choose fine?
A: Only when the drawing specifies fine / a non-default pitch.
Q: Are catalog SHCS coarse?
A: Predominantly yes unless the SKU marks fine—check the product page or ask sales.
Q: Where is the full chart?
A: Coarse vs fine thread pitch.