Xem Studiomeasured geometry

Library › Hardware › Hex cap screws and heavy hex screws, inch 7/8 to 1-1/2 (ASME…

heavy hex screw 1-1/4-7 UNC envelope

heavy hex screw 1-1/4-7 UNC envelope: hex head 2.000 in across flats x .813 in high (F max, H max), plain shank Ø1.2500 in (major diameter, thread not drawn), 4 in under the head (example length, Xem choice); published thread length LT 2.750 in (L ≤ 6 in)

Exact dimensions. True size, no tolerance added. Threads are plain cylinders at the major diameter.

STEP STL free, CC BY 4.0 (credit "Xem Studio")

Dimensions

styleheavy hex screw
size (in)1-1/4
UNC / UNF TPI7 / 12
E body dia max / min1.2500 / 1.223
F across flats max / min2.000 / 1.938
G across corners max / min2.309 / 2.209
H head height max / min.813 / .749
J wrenching height min (cap only)–
LT thread length, L ≤ 6 in2.750
LT thread length, L > 6 in3.000
file: F max / H max (mm)50.8 / 20.65
Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.
Set it up →

From the full sheet

Hex cap screws and heavy hex screws, inch 7/8 to 1-1/2 (ASME B18.2.1): across flats F, head height H, thread length LT: every size, notes, mating features and sources. What are the head size, head height and thread length of a 7/8, 1, 1-1/8, 1-1/4, 1-3/8 or 1-1/2 inch hex cap screw or heavy hex screw?

Other sizes