18mm Keys | McMaster-Carr

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	System of Measurement System of Measurement

Metric

	Width Width	Show

18mm

	Width Width	Hide

	Overall Length Overall Length

	Height Height

	Key Type Key Type


Straight	Rounded

Tapered

	Material Material

Stainless Steel

Steel

	Tolerance Rating Tolerance Rating

Undersized

Oversized

	Minimum Hardness Minimum Hardness

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

	Specifications Met Specifications Met

	For Machine Table T-Slot Width For Machine Table T-Slot Width

18mm

	Finish Finish

Zinc Plated

	Shape Shape

Rectangle

	For Mounting Screw Size For Mounting Screw Size

	End Height End Height

10.210mm

	Head Height Head Height

18mm

	Head Length Head Length

18mm

	Rate of Taper Rate of Taper

1 mm per 100 mm

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27 Products

Rounded Machine Keys

When installed, these keys fill oval keyways completely, reducing stress on the key and shaft. Using them in a closed keyway keeps them from sliding along the shaft axis. The rounded ends make it easy to slide gears, hubs, and other components into place. These are also known as feather keys. Machine keys are often the same material and as hard or harder than the shaft and other components with which they are used. To use a key as a sacrificial part, choose a softer key that will shear off when parts are exposed to excessive force, preventing damage to expensive equipment.

Steel keys offer good strength. Slightly smaller than the size listed in the table, undersized keys are the choice when you need a slightly looser fit or when you have an inconsistent keyway. Use them when parts need to be taken apart frequently, such as for maintenance or prototyping.

Metric keys conform to DIN 6885 standards.

For technical drawings and 3-D models, click on a part number.

		Tolerance
Lg.	Tolerance Rating	Ht.	Wd.	Specifications Met	Pkg. Qty.		Pkg.
1018-1045 Carbon Steel
11mm × 18mm
50mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	DIN 6885	1	000000000	00000
56mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	DIN 6885	1	000000000	0000
63mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	DIN 6885	1	000000000	0000
70mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	DIN 6885	1	000000000	0000
80mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	DIN 6885	1	000000000	0000
90mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	DIN 6885	1	000000000	0000
100mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	DIN 6885	1	000000000	00000
110mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	DIN 6885	1	000000000	00000

Machine Keys

Steel keys offer good strength.

Slightly smaller than the size listed in the table, undersized keys are the choice when you need a slightly looser fit or when you have an inconsistent keyway. Use them when parts need to be taken apart frequently, such as for maintenance or prototyping.

For technical drawings and 3-D models, click on a part number.

		Tolerance
Lg.	Tolerance Rating	Ht.	Wd.	Minimum Hardness	Specifications Met	Pkg. Qty.		Pkg.
1018-1045 Carbon Steel
11mm × 18mm
50mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	Not Rated	DIN 6885	1	000000000	00000
70mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	Not Rated	DIN 6885	1	000000000	0000
80mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	Not Rated	DIN 6885	1	000000000	0000
100mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	Not Rated	DIN 6885	1	000000000	0000
110mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	Not Rated	DIN 6885	1	000000000	0000

Tapered Gib Keys

These keys have a tapered body that wedges in to the keyway for a more secure fit than standard machine keys. The gib head makes these keys easy to remove when parts need to be taken apart frequently, such as for maintenance or prototyping. Keys are tapered along their length. Use them to connect gears and other components with tapered keyways to shafts. Keys are made of steel.

The height of metric keys decreases by 1 mm for every 100 mm of length. They meet DIN 6887, an international standard for machine keys.

For technical drawings and 3-D models, click on a part number.

	Tolerance		Head
Lg.	Ht.	Wd.	Ht.	Lg.	End Ht.	Rate of Taper	Specifications Met		Each
1018-1045 Carbon Steel
11mm × 18mm
90mm	0.000mm to 0.200mm	-0.043mm to 0.000mm	18mm	18mm	10.210mm	1 mm per 100 mm	DIN 6887	000000000	000000

Machine Key Stock

Cut this square or rectangular key stock to length to create a straight machine key. Straight keys are the most common type of key. Machine keys are often the same material and as hard or harder than the shaft and other components with which they are used. To use a key as a sacrificial part, choose a softer key that will shear off when parts are exposed to excessive force, preventing damage to expensive equipment.

Steel key stock is an economical choice with good strength. 4140 alloy steel key stock has greater strength and toughness after hardening than carbon steel, making it useful for high-stress applications. Zinc-plated steel key stock resists corrosion in wet environments.

Stainless steel key stock is more corrosion resistant than steel key stock. 18-8 stainless steel key stock offers a balance of strength and corrosion resistance. It may be mildly magnetic. 316 stainless steel key stock has the best corrosion resistance of our stainless steel key stock and may be mildly magnetic.

Slightly larger than the size listed in the table, oversized stock fits tightly in a keyway. Press it into place for use in high-torque applications or to replace a key in a worn keyway. Slightly smaller than the size listed in the table, undersized stock is the choice when you need a slightly looser fit or when you have an inconsistent keyway. Use it when parts need to be taken apart frequently, such as for maintenance or prototyping.

Key stock that meets DIN 6880 conforms to DIN standards for undersized keys.

1018-1045 Carbon Steel

		Tolerance
Ht. × Wd.	Tolerance Rating	Ht.	Wd.	Minimum Hardness	Specifications Met		Each
305mm Lg.
7mm × 18mm	Undersized	-0.090mm to 0.000mm	-0.043mm to 0.000mm	Rockwell B87	DIN 6880	000000000	000000
11mm × 18mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	Rockwell B87	DIN 6880	000000000	00000
18mm × 18mm	Undersized	-0.043mm to 0.000mm	-0.043mm to 0.000mm	Rockwell B87	DIN 6880	000000000	00000
1,000mm Lg.
11mm × 18mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	Rockwell B87	DIN 6880	000000000	00000
18mm × 18mm	Undersized	-0.043mm to 0.000mm	-0.043mm to 0.000mm	Rockwell B87	DIN 6880	000000000	00000

4140 Alloy Steel

		Tolerance
Ht. × Wd.	Tolerance Rating	Ht.	Wd.	Minimum Hardness	Specifications Met		Each
305mm Lg.
11mm × 18mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	Rockwell B90	DIN 6880	000000000	000000

Zinc-Plated 1018-1045 Carbon Steel

		Tolerance
Ht. × Wd.	Tolerance Rating	Ht.	Wd.	Minimum Hardness	Specifications Met		Each
305mm Lg.
7mm × 18mm	Oversized	0.000mm to 0.076mm	0.000mm to 0.076mm	Rockwell B87	DIN 6880	000000000	000000
11mm × 18mm	Oversized	0.000mm to 0.076mm	0.000mm to 0.076mm	Rockwell B87	DIN 6880	000000000	00000
18mm × 18mm	Oversized	0.000mm to 0.076mm	0.000mm to 0.076mm	Rockwell B87	DIN 6880	000000000	00000

18-8 Stainless Steel

		Tolerance
Ht. × Wd.	Tolerance Rating	Ht.	Wd.	Minimum Hardness	Specifications Met		Each
305mm Lg.
18mm × 18mm	Oversized	0.000mm to 0.076mm	0.000mm to 0.076mm	Rockwell B82	DIN 178	000000000	000000

316 Stainless Steel

		Tolerance
Ht. × Wd.	Tolerance Rating	Ht.	Wd.	Minimum Hardness	Specifications Met		Each
305mm Lg.
11mm × 18mm	Undersized	-0.090mm to 0.000mm	-0.043mm to 0.000mm	Rockwell B86	DIN 6880	000000000	0000000
1,000mm Lg.
11mm × 18mm	Undersized	-0.110mm to 0.000mm	-0.043mm to 0.000mm	Rockwell B85	DIN 6880	000000000	000000

Fixture Keys

Rectangular

Sized to fit with precision in machine table T-slots, use these keys to locate fixtures and vises on your machine table. They mount to the underside of your fixture or vise with a socket head cap screw.

For technical drawings and 3-D models, click on a part number.

Metric

Rectangular
For Machine Table T-Slot Wd., mm	Lg., mm	Wd., mm	Ht., mm	Wd. Tolerance, mm	For Mounting Screw Size	Mounting Fasteners Included	Material		Each
18	22	18	10	-0.00011 to 0	M6	No	Steel	0000000	000000