Skip to content

McMaster 91251A242 Black-Oxide Alloy Steel Socket Head Screw 10-24 Thread Size, 1/2" Long PK100

Original price $51.72 - Original price $51.72
Original price
$51.72
$51.72 - $51.72
Current price $51.72

Made of alloy steel, these screws are the standard for high-strength fastening. Use them in high-load applications such as dies, presses, and heavy equipment. The deep, six-point socket keeps the hex key from slipping out and damaging the drive.

Length is measured from under the head.

Black-Oxide Alloy SteelTypically chosen for their appearance, these screws have a dark, matte coating to create a finished look. They offer minimal corrosion resistance, so they're best for dry environments.

Thread
Size

10-24

Spacing

Coarse

Type

UNRC

Fit

Unified Standard Class 3A

Direction

Right Hand

Socket Head Profile

Standard

Fastener Head Type

Socket

Drive Style

Hex

Length

1/2"

Head
Diameter

5/16"

Height

0.19"

Threading

Fully Threaded

Tensile Strength

170,000 psi

Specifications Met

ASTM A574

Certificate Form

Digital

Certificate Type

Material Certificate with Traceable Lot Number

Drive Size

5/32"

Hardness

Rockwell C37

Material

Black-Oxide Alloy Steel

Performance

High Strength

Screw Size Decimal Equivalent

0.19"

System of Measurement

Inch

Tip Type

Flat

Country of Origin

United States

DFARS Compliance

Specialty Metals Compliant (252.225-7009)

Export Control Classification Number (ECCN)

EAR99

REACH Compliance

REACH (EC 1907/2006) (02/04/2026, 253 SVHC) Compliant

RoHS Compliance

RoHS 3 (2015/863/EU) Compliant

Schedule B Number

731815.9000

U.S.–Mexico–Canada Agreement (USMCA) Qualifying

Yes