Threads / Series directory
UNF
thread sizes.
24 distinct nominal diameter–pitch combinations. Open a size for its differences and exact next steps.
Choose the complete designation
20 of 24 sizes have a matching reviewed drill-chart row. Other sizes provide an equation estimate with no rounded drill recommendation.
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| Designation | Major Ø · in / mm | TPI | Pitch · mm | Drill evidence | Next step |
|---|---|---|---|---|---|
| #0-80 UNF | 0.06 / 1.524 | 80 | 0.3175 | Chart row | Tap-drill lookup → |
| #1-72 UNF | 0.073 / 1.8542 | 72 | 0.352778 | Chart row | Tap-drill lookup → |
| #2-64 UNF | 0.086 / 2.1844 | 64 | 0.396875 | Chart row | Tap-drill lookup → |
| #3-56 UNF | 0.099 / 2.5146 | 56 | 0.453571 | Chart row | Tap-drill lookup → |
| #4-48 UNF | 0.112 / 2.8448 | 48 | 0.529167 | Chart row | Tap-drill lookup → |
| #5-44 UNF | 0.125 / 3.175 | 44 | 0.577273 | Chart row | Tap-drill lookup → |
| #6-40 UNF | 0.138 / 3.5052 | 40 | 0.635 | Chart row | Tap-drill lookup → |
| #8-36 UNF | 0.164 / 4.1656 | 36 | 0.705556 | Chart row | Tap-drill lookup → |
| #10-32 UNF | 0.19 / 4.826 | 32 | 0.79375 | Chart row | Tap-drill lookup → |
| #12-28 UNF | 0.216 / 5.4864 | 28 | 0.907143 | Chart row | Tap-drill lookup → |
| 1/4-28 UNF | 0.25 / 6.35 | 28 | 0.907143 | Chart row | Tap-drill lookup → |
| 5/16-24 UNF | 0.3125 / 7.9375 | 24 | 1.058333 | Chart row | Tap-drill lookup → |
| 3/8-24 UNF | 0.375 / 9.525 | 24 | 1.058333 | Chart row | Tap-drill lookup → |
| 7/16-20 UNF | 0.4375 / 11.1125 | 20 | 1.27 | Chart row | Tap-drill lookup → |
| 1/2-20 UNF | 0.5 / 12.7 | 20 | 1.27 | Chart row | Tap-drill lookup → |
| 9/16-18 UNF | 0.5625 / 14.2875 | 18 | 1.411111 | Chart row | Tap-drill lookup → |
| 5/8-18 UNF | 0.625 / 15.875 | 18 | 1.411111 | Chart row | Tap-drill lookup → |
| 3/4-16 UNF | 0.75 / 19.05 | 16 | 1.5875 | Chart row | Tap-drill lookup → |
| 7/8-14 UNF | 0.875 / 22.225 | 14 | 1.814286 | Chart row | Tap-drill lookup → |
| 1-12 UNF | 1 / 25.4 | 12 | 2.116667 | Chart row | Tap-drill lookup → |
| 1 1/8-12 UNF | 1.125 / 28.575 | 12 | 2.116667 | Equation only | Tap-drill lookup → |
| 1 1/4-12 UNF | 1.25 / 31.75 | 12 | 2.116667 | Equation only | Tap-drill lookup → |
| 1 3/8-12 UNF | 1.375 / 34.925 | 12 | 2.116667 | Equation only | Tap-drill lookup → |
| 1 1/2-12 UNF | 1.5 / 38.1 | 12 | 2.116667 | Equation only | Tap-drill lookup → |
Before treating a size as a match
Confirm pitch, thread profile and complete drawing requirements. A nominal diameter match does not establish mating compatibility.
Read the designation and class →