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 as 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 are strong and easy to machine. Since steel is the most common material, these keys work in many applications. Steel keys rust when exposed to moisture, so they should only be used in dry environments. Zinc-plated steel keys resist corrosion in wet environments. Slightly larger than the size listed in the table, oversized keys fit tightly in a keyway. Press them 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 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.
Keys that meet ANSI B17.1 specifications conform to ANSI standards for dimensions and tolerances.
For technical drawings and 3-D models, click on a part number.
Tolerance | |||||||
|---|---|---|---|---|---|---|---|
| Lg. | Tolerance Rating | Ht. | Wd. | Specifications Met | Pkg. Qty. | Pkg. | |
1008-1045 Carbon Steel | |||||||
1/8" × 1/8" | |||||||
| 1/2" | Oversized | 0.000" to 0.001" | 0.000" to 0.001" | ANSI B17.1 Class 2 | 5 | 000000000 | 00000 |
| 1/2" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | ANSI B17.1 Class 1 | 5 | 000000000 | 0000 |
| 3/4" | Oversized | 0.000" to 0.001" | 0.000" to 0.001" | ANSI B17.1 Class 2 | 5 | 000000000 | 0000 |
| 3/4" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | ANSI B17.1 Class 1 | 5 | 000000000 | 0000 |
| 1" | Oversized | 0.000" to 0.001" | 0.000" to 0.001" | ANSI B17.1 Class 2 | 5 | 000000000 | 0000 |
| 1" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | ANSI B17.1 Class 1 | 5 | 000000000 | 0000 |
Zinc-Plated 1008-1045 Carbon Steel | |||||||
1/8" × 1/8" | |||||||
| 1/2" | Oversized | 0.000" to 0.001" | 0.000" to 0.001" | ANSI B17.1 Class 2 | 5 | 000000000 | 00000 |
| 1/2" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | ANSI B17.1 Class 1 | 5 | 000000000 | 0000 |
| 3/4" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | ANSI B17.1 Class 1 | 5 | 000000000 | 0000 |
| 1" | Oversized | 0.000" to 0.001" | 0.000" to 0.001" | ANSI B17.1 Class 2 | 5 | 000000000 | 00000 |
| 1" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | ANSI B17.1 Class 1 | 5 | 000000000 | 0000 |
Machine Keys
Straight keys, with a square or rectangular cross section, are the most common type of key. Install them in keyways to transmit torque from shafts to gears and other components. Machine keys are often the same material as 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 are strong and easy to machine. Since steel is the most common material, these keys work in many applications. Steel keys rust when exposed to moisture, so they should only be used in dry environments.
18-8 stainless steel keys offer a balance of strength and corrosion resistance. They may be mildly magnetic.
Slightly larger than the size listed in the table, oversized keys fit tightly in a keyway. Press them 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 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.
Keys that meet ANSI B17.1 specifications conform to ANSI standards for dimensions and tolerances.
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. | |
1008-1045 Carbon Steel | ||||||||
1/8" × 1/8" | ||||||||
| 1/4" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B50 | ANSI B17.1 Class 1 | 10 | 000000000 | 000000 |
| 1/2" | Oversized | 0.000" to 0.002" | 0.000" to 0.002" | Rockwell B50 | __ | 10 | 000000000 | 0000 |
| 1/2" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B50 | ANSI B17.1 Class 1 | 10 | 000000000 | 0000 |
| 3/4" | Oversized | 0.000" to 0.002" | 0.000" to 0.002" | Rockwell B50 | __ | 10 | 000000000 | 00000 |
| 3/4" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B50 | ANSI B17.1 Class 1 | 10 | 000000000 | 0000 |
| 1" | Oversized | 0.000" to 0.002" | 0.000" to 0.002" | Rockwell B50 | __ | 10 | 000000000 | 0000 |
| 1" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B50 | ANSI B17.1 Class 1 | 10 | 000000000 | 0000 |
| 1 1/4" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B50 | ANSI B17.1 Class 1 | 10 | 000000000 | 0000 |
| 1 1/2" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B50 | ANSI B17.1 Class 1 | 10 | 000000000 | 00000 |
18-8 Stainless Steel | ||||||||
1/8" × 1/8" | ||||||||
| 1/4" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B82 | __ | 10 | 000000000 | 0000 |
| 1/2" | Oversized | 0.000" to 0.003" | 0.000" to 0.003" | Rockwell B82 | __ | 10 | 000000000 | 0000 |
| 1/2" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B82 | __ | 10 | 000000000 | 0000 |
| 3/4" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B82 | __ | 10 | 000000000 | 0000 |
| 1" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B82 | __ | 10 | 000000000 | 0000 |
| 1 1/4" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B82 | __ | 10 | 000000000 | 00000 |
| 1 1/2" | Undersized | -0.002" to 0.000" | -0.002" to 0.000" | Rockwell B82 | __ | 10 | 000000000 | 00000 |
Woodruff Keys
Woodruff keys work well near shaft shoulders, where a standard open keyway would create too much stress. They are also often used on tapered shafts. These keys have a rounded shape that makes them easy to remove when parts need to be taken apart frequently, such as for maintenance or prototyping. Because they're usually shorter than standard machine keys, they work best in light duty applications. Use them to connect gears and other components to shafts. Also known as half moon keys.
Steel keys offer good strength.
316 stainless steel keys have excellent corrosion resistance, but aren't as strong as steel keys. They may be mildly magnetic.
Inch keys conform to ANSI B17.2 standards for dimensions and tolerances.
For technical drawings and 3-D models, click on a part number.
Tolerance | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Woodruff Key Number | Wd. | For Keyway Dia. | Ht. | Lg. | Wd. | Ht. | Specifications Met | Pkg. Qty. | Pkg. | |
1018-1045 Carbon Steel | ||||||||||
| 3 | 1/8" | 1/2" | 0.194" | 0.491" | 0.000" to 0.001" | -0.006" to 0.000" | ANSI B17.2 | 100 | 000000000 | 000000 |
| 5 | 1/8" | 5/8" | 0.24" | 0.612" | 0.000" to 0.001" | -0.006" to 0.000" | ANSI B17.2 | 100 | 000000000 | 00000 |
| 7 | 1/8" | 3/4" | 0.303" | 0.74" | 0.000" to 0.001" | -0.006" to 0.000" | ANSI B17.2 | 100 | 000000000 | 00000 |
| 213 | 1/8" | 3/8" | 0.172" | 0.374" | 0.000" to 0.001" | -0.005" to 0.000" | ANSI B17.2 | 50 | 000000000 | 00000 |
8630 Alloy Steel | ||||||||||
| 3 | 1/8" | 1/2" | 0.194" | 0.491" | 0.000" to 0.001" | -0.006" to 0.000" | ANSI B17.2 | 100 | 000000000 | 00000 |
| 5 | 1/8" | 5/8" | 0.24" | 0.612" | 0.000" to 0.001" | -0.006" to 0.000" | ANSI B17.2 | 100 | 000000000 | 00000 |
| 7 | 1/8" | 3/4" | 0.303" | 0.74" | 0.000" to 0.001" | -0.006" to 0.000" | ANSI B17.2 | 50 | 000000000 | 00000 |
| 213 | 1/8" | 3/8" | 0.172" | 0.374" | 0.000" to 0.001" | -0.005" to 0.000" | ANSI B17.2 | 50 | 000000000 | 00000 |
316 Stainless Steel  | ||||||||||
| 3 | 1/8" | 1/2" | 0.194" | 0.491" | 0.000" to 0.001" | -0.006" to 0.000" | ANSI B17.2 | 5 | 000000000 | 00000 |
| 5 | 1/8" | 5/8" | 0.25" | 0.612" | 0.000" to 0.001" | -0.005" to 0.000" | ANSI B17.2 | 5 | 000000000 | 00000 |
| 7 | 1/8" | 3/4" | 0.303" | 0.74" | 0.000" to 0.001" | -0.006" to 0.000" | ANSI B17.2 | 1 | 000000000 | 0000 |
| 213 | 1/8" | 3/8" | 0.172" | 0.374" | 0.000" to 0.001" | -0.005" to 0.000" | ANSI B17.2 | 5 | 000000000 | 00000 |
High-Profile Woodruff Keys
Feet prevent these keys from rocking in the keyseat, making it easier to install gears and other components. Woodruff keys work well near shaft shoulders, where a standard open keyway would create too much stress. They are also often used on tapered shafts. Because they're usually shorter than standard machine keys, they work best in light duty applications. Keys are made of steel. Also known as hi-pro keys.
For technical drawings and 3-D models, click on a part number.
Tolerance | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Woodruff Key Number | Wd. | Ht. | For Keyway Dia. | Lg. | Wd. | Ht. | Feet Ht. | Pkg. Qty. | Pkg. | |
1018-1045 Carbon Steel | ||||||||||
| 3 | 1/8" | 0.194" | 1/2" | 0.531" | 0.000" to 0.001" | 0.000" to 0.006" | 0.056" | 5 | 000000000 | 00000 |
| 5 | 1/8" | 0.24" | 5/8" | 0.656" | 0.000" to 0.001" | 0.000" to 0.006" | 0.056" | 5 | 000000000 | 0000 |
| 7 | 1/8" | 0.303" | 3/4" | 0.781" | 0.000" to 0.001" | 0.000" to 0.006" | 0.057" | 5 | 000000000 | 0000 |