Dimensions, drill sizes and wrench sizes for 7/16-14 UNC.
Designation
7/16-14 UNC
Major (outside) diameter
11.112 mm · 0.4375"
Pitch
1.814 mm · 14 TPI
Pitch diameter
9.934 mm · 0.3911"
Minor diameter (external)
8.887 mm · 0.3499"
Minor diameter (internal)
9.149 mm · 0.3602"
Recommended tap drill
U · 9.35 mm · ≈75% thread
Clearance hole
Close 29/64" · Normal 15/32" · Loose 1/2" - nominal + 1/64" / 1/32" / 1/16" to the nearest standard drill (common shop practice).
Hex head (across flats)
5/8"
Socket key (across flats)
3/8"
Close 29/64" · Normal 15/32" · Loose 1/2" - nominal + 1/64" / 1/32" / 1/16" to the nearest standard drill (common shop practice).
Tightening torque estimate
Target preload is 75% of proof load; torque is estimated from T = K · F · d.
Proof-load preload and estimated tightening torque for 7/16-14 UNC by fastener grade or property class.
Grade / class
Stress area
Preload
Torque
SAE Grade 2
0.1063 in²
4385 lbf
32 lb·ft · 384 lb·in
SAE Grade 5
0.1063 in²
6777 lbf
49 lb·ft · 593 lb·in
SAE Grade 8
0.1063 in²
9568 lbf
70 lb·ft · 837 lb·in
Strengths are SAE J429 for this diameter band. J429 steps down with size: Grade 2 falls to 33 ksi proof above 3/4 in and Grade 5 to 74 ksi above 1 in, so these figures are not the small-size values. The Grade 2 row applies to bolts up to 6 in long; a longer Grade 2 bolt of the same diameter drops to 33 ksi proof.
These figures assume a nut factor of K = 0.20 (dry / as-received steel). K captures thread and head friction and can swing torque by 30% or more - a lubricated joint needs noticeably less. Change the lubrication assumption in the bolt-torque calculator.
Put 7/16-14 UNC on a job sheet
The bolt schedule collects the fasteners for one job onto a single sheet - tap drill, wrench size, grade and tightening torque on every line, taken straight from pages like this one. Free schedules hold 3 lines and are saved in this browser only.
For a 7/16-14 UNC thread, drill the hole with a U tap drill (9.35 mm) before tapping. That produces roughly 75% thread engagement, the usual target for a strong, tappable hole. The mating bolt has a major diameter of 11.112 mm and a pitch of 1.814 mm (14 TPI).
To pass a 7/16-14 UNC bolt through a part rather than thread it, use a clearance hole: Close 29/64" · Normal 15/32" · Loose 1/2" - nominal + 1/64" / 1/32" / 1/16" to the nearest standard drill (common shop practice)..
All values are generated from the standard thread formulas (ISO 68-1 / ASME B1.1) and published standard tables - not hand-entered. See the full reference.
Frequently asked questions
What drill size do I need to tap a 7/16-14 UNC thread?
Drill U (9.35 mm) before tapping 7/16-14 UNC. That leaves roughly 75% thread engagement, the usual target for a strong hole that still taps cleanly.
Is 7/16-14 UNC a coarse or fine thread?
7/16-14 UNC is a Unified coarse (UNC) thread at 14 threads per inch, the default inch series for general fastening in this diameter.
What size clearance hole does a 7/16-14 UNC bolt need?
Close 29/64" · Normal 15/32" · Loose 1/2" - nominal + 1/64" / 1/32" / 1/16" to the nearest standard drill (common shop practice). A clearance hole lets the 7/16-14 UNC bolt pass through the part instead of threading into it.
How much torque should I use on a 7/16-14 UNC bolt?
Estimated tightening torque for 7/16-14 UNC runs from 32 lb·ft (SAE Grade 2) to 70 lb·ft (SAE Grade 8), targeting 75% of proof load with a dry nut factor of K = 0.20. Lubricated threads need noticeably less torque.
Nearest standard metric sizes by major diameter. These are substitutes by size only - the thread forms are not interchangeable, so never run one into the other.