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1/4-28 UNF UNF bolt size
7/16 wrench
wrench size for 1/4-28 UNF UNF bolt
1/4-28 UNF UNF bolt — Precision instruments, aerospace.
Full specification
| System | Imperial UNF (fine) |
| Nominal diameter | 0.25 in (6.35 mm) |
| Thread pitch | 28 TPI |
| Wrench size | 7/16 |
| Tap drill | #3 (5.4 mm) |
| Clearance hole | 17/64 |
| Common grade / class | Grade 5 |
| Typical torque | 12 Nm (8.85 ft·lb) |
🔧 Torque unit converter
Pre-filled with typical torque for 1/4-28 UNF (Grade 5).
About 1/4-28 UNF UNF bolts
Precision instruments, aerospace.
UNF (Unified National Fine) thread has more threads per inch than UNC (coarse). 1/4-28 UNF has 28 threads per inch.
Fine threads provide better vibration resistance and finer adjustment, commonly used in automotive and aerospace applications.
Frequently asked questions
- What size wrench fits 1/4-28 UNF bolt?
- 1/4-28 UNF bolt uses a 7/16 wrench.
- What is the torque for 1/4-28 UNF bolt?
- Typical torque for 1/4-28 UNF UNF bolt in Grade 5 is about 12 Nm (8.85 ft·lb).
- What is UNF thread?
- UNF (Unified National Fine) thread has more threads per inch than UNC. 1/4-28 UNF has 28 TPI.