Grooved Pins / Studs
Grooved pins are non-threaded press-fit fasteners, a type of shear-resistant fastener that is pressed into an appropriate-sized hold, providing the proper interference fit to lock the fastener in place. They’re most commonly used as locking devices, pivots, bearing faces, or locating elements where there is not a high degree of end load.
How They’re Made and How They Work
The groove of a grooved pin is formed by a swaging operation in which three tools penetrate the nominal diameter of the metal at 120° intervals. This penetration displaces a controlled amount of metal to each side of the grooving tool, forming a raised portion along the side of each groove.
The crest of these raised portions forms the expanded diameter or “Dx” dimension. The Dx is a few thousandths larger than the pin’s nominal diameter “D.” The amount of expansion varies with the diameter of the pin, the material being grooved, and the groove style.
When a grooved pin is used, the hole into which the pin is to be inserted is drilled a few thousandths larger than the nominal diameter of the pin. The hole must never be smaller than the nominal diameter of the pin. When the expanded portion of the pin is compressed by insertion into the hole, radial holding forces are generated. These radial forces lock the pin securely into the drilled hole.
Standard Groove Pins
We manufacture grooved pins in a wide range of standard dimensions and many different groove types. We know that customers must be flexible and respond quickly to demanding environments, so we have partnered with stocking distributors for immediate delivery on standard pins.
Custom Groove Pins
Driv-Lok is known for short lead times on custom pins. We haven’t settled on just having the shortest lead time; we continuously look to improve it because, in today’s competitive environment, it’s all about time, and every day counts. We offer custom grooved pins in a wide variety of diameters, lengths, and end configurations.
Grooved Pin Diameter / Shaft Size /Torque Relationships
This table is a guide for selecting the proper-size DRIV-LOK Grooved Pin to use for fastening machine members to shafts of given sizes and for specific load requirements. Torque and horsepower ratings are based on pins made of cold-finished, low-carbon steel, and a safety factor of 8 is assumed.
| Recommended pin diameter for various shaft sizes and torque transmitted by pin in double shear | |||
| Shaft size | Pin diameter | Torque inch lbs. | H.P. at 100 R.P.M. |
| 3⁄16 | 1⁄16 | 4.8 | .007 |
| 7⁄32 | 5⁄64 | 8.5 | .013 |
| 1⁄4 | 3⁄32 | 13.9 | .022 |
| 5⁄16 | 7⁄64 | 23.8 | .038 |
| 3⁄8 | 1⁄8 | 37.5 | 0.60 |
| 7⁄16 | 5⁄32 | 62.9 | .100 |
| 1⁄2 | 5⁄32 | 71.9 | .114 |
| 9⁄16 | 3⁄16 | 116.4 | .185 |
| 11⁄16 | 7⁄32 | 193.8 | .307 |
| 3⁄4 | 1⁄4 | 275.6 | .437 |
| 13⁄16 | 1⁄4 | 298.6 | .474 |
| 7⁄8 | 1⁄4 | 322 | .510 |
| 15⁄16 | 15⁄16 | 449 | .712 |
| 1 | 15⁄16 | 479 | .759 |
| 11⁄16 | 15⁄16 | 509 | .807 |
| 11⁄8 | 3⁄8 | 773 | 1.23 |
| 13⁄16 | 3⁄8 | 816 | 1.30 |
| 11⁄4 | 3⁄8 | 859 | 1.36 |
| 15⁄16 | 7⁄16 | 1230 | 1.95 |
| 13⁄8 | 7⁄16 | 1289 | 2.05 |
| 17⁄16 | 7⁄16 | 1348 | 2.14 |
| 11⁄2 | 1⁄2 | 1838 | 2.92 |
| Recommended pin diameter for various shaft sizes and torque transmitted by pin in double shear | Slotted spring pins | ||||
| Pin diameter | Low carbon | Shear-proof alloy steel (RC 40-48) | Corrosion resistant steel | Brass | 1074 steel and 420 SS |
| 1⁄16 | 410 | 720 | 540 | 250 | 430 |
| 3⁄32 | 890 | 1,600 | 1,240 | 560 | 1,150 |
| 1⁄8 | 1,600 | 2,820 | 2,200 | 990 | 1,875 |
| 5⁄32 | 2,300 | 4,520 | 3,310 | 1,540 | 2,750 |
| 3⁄16 | 3,310 | 6,400 | 4,760 | 2,200 | 4,150 |
| 7⁄32 | 4,510 | 8,770 | 6,480 | 3,020 | 5,850 |
| 1⁄4 | 5,880 | 11,500 | 8,460 | 3,950 | 7,050 |
| 5⁄16 | 7,660 | 17,900 | 12,700 | 6,170 | 10,800 |
| 3⁄8 | 11,000 | 26,000 | 18,200 | 9,050 | 16,300 |
| 7⁄16 | 15,000 | 35,200 | 24,800 | 12,100 | 19,800 |
| 1⁄2 | 19,600 | 46,000 | 32,400 | 15,800 | 27,100 |