What size wrench or spanner fits M24?

M24 bolt uses a 36 mm wrench or spanner, measured across the flats of the hex head.

What is the torque for M24?

A typical tightening torque for M24 bolt in 8.8 on dry threads is about 550 Nm (405.9 ft·lb). Always confirm against the manufacturer spec for important joints.

What thread pitch and tap drill does M24 use?

M24 bolt has a thread pitch of 3.0 mm and uses a 21 mm tap drill, with a 26 mm clearance hole.

What is M24 used for?

M24 is commonly used in heavy structural, bridges, industrial machinery. It is one of the most popular sizes in its category.

What is the closest imperial size to M24?

The closest imperial size to M24 is approximately ~1 inch, though they are not exactly interchangeable.

Home › Metric Bolts › M24

M24 bolt size

36 mm wrench

across-flats spanner / socket size for M24

M24 bolt — Heavy structural, bridges, industrial machinery.

Full specification

System	Metric coarse
Nominal diameter	24 mm
Thread pitch	3.0 mm
Wrench / spanner (across flats)	36 mm
Tap drill	21 mm
Clearance hole	26 mm
Common grade / class	8.8
Typical torque	550 Nm (405.9 ft·lb)
Closest other-system size	~1 inch

🔧 Torque unit converter

Newton-metres (Nm) Foot-pounds (ft·lb) Inch-pounds (in·lb)

Pre-filled with the typical torque for M24 (8.8, dry). Edit any field to convert.

⚠️ Torque values here are general references for 8.8 on clean, dry threads. Lubrication, coatings, and the joint material change the figure significantly. For structural, automotive, or safety-critical work, always use the torque specified by the manufacturer or engineer.

About M24

Heavy structural, bridges, industrial machinery.

A 21 mm tap drill is correct for M24 coarse thread. The standard clearance hole is 26 mm.

M24 is part of the ISO metric coarse thread series, defined in ISO 261. The wrench size 36 mm is measured across the flats of the hex head.

Common applications

M24 bolts are widely used in:

Heavy structural, bridges, industrial machinery
General machinery and equipment assembly
Automotive components and repairs
Structural connections (when specified by engineer)
Furniture and fixture assembly

Material and grade information

The typical grade for M24 is 8.8. This indicates:

Property class 8.8: Medium carbon steel, quenched and tempered
Tensile strength: 800 MPa minimum
Yield strength: 640 MPa minimum (0.2% proof stress)
Common coatings: Zinc plated, hot-dip galvanized, or plain

Frequently asked questions

What size wrench or spanner fits M24?: M24 bolt uses a 36 mm wrench or spanner, measured across the flats of the hex head.
What is the torque for M24?: A typical tightening torque for M24 bolt in 8.8 on dry threads is about 550 Nm (405.9 ft·lb). Always confirm against the manufacturer spec for important joints.
What thread pitch and tap drill does M24 use?: M24 bolt has a thread pitch of 3.0 mm and uses a 21 mm tap drill, with a 26 mm clearance hole.
What is M24 used for?: M24 is commonly used in heavy structural, bridges, industrial machinery. It is one of the most popular sizes in its category.
What is the closest imperial size to M24?: The closest imperial size to M24 is approximately ~1 inch, though they are not exactly interchangeable.