TECHNICAL BULLETINInstallation of TA Thread-Rolling Screws for MetalsTA thread-rolling screws are an excellent choice for usewith drilled, extruded, punched or molded holes in ductilemetals and castings. The triangular out-of-round shapeforms strong threads by work-hardening the metal hostmaterial without creating unwanted chips or slivers. The design requires low installation torque and providesexcellent resistance to loosening caused by vibration.
Recommended Hole Diameters for Cold-Rolled Steel Sheets and Plates
All dimensions in inches| Application | Light | Medium-Light | Medium-Heavy | Full Strength | Extra Strength |
| ThreadEngagement Percentage | 90% | 85% | 80% | 75% | 70% |
| Thread | MaterialThickness | HoleDiameter | MaterialThickness | HoleDiameter | MaterialThickness | HoleDiameter | MaterialThickness | HoleDiameter | MaterialThickness | HoleDiameter |
| 2-56 | .017-.034 | .0756 | .034-.052 | .0761 | .052-.073 | .0767 | .073-.095 | .0773 | .095-.169 | .0779 |
| 4-40 | .022-.045 | .0974 | .045-.067 | .0982 | .067-.095 | .0990 | .095-.126 | .0998 | .126-.157 | .1006 |
| 6-32 | .028-.066 | .1197 | .066-.083 | .1207 | .083-.117 | .1218 | .117-.152 | .1288 | .152-.193 | .1238 |
| 8-32 | .033-.066 | .1457 | .066-.098 | .1467 | .098-.141 | .1478 | .141-.180 | .1488 | .180-.230 | .1498 |
| 10-24 | .038-.079 | .1656 | .079-.114 | .1670 | .114-.162 | .1683 | .162-.209 | .1697 | .209-.266 | .1710 |
| 10-32 | .038-.079 | .1717 | .079-.114 | .1727 | .114-.162 | .1738 | .162-.209 | .1748 | .209-.266 | .1758 |
| 12-24 | .043-.086 | .1916 | .086-.130 | .1930 | .130-.184 | .1943 | .184-.238 | .1957 | .238-.302 | .1970 |
| 1/4-20 | .050-.100 | .2208 | .100-.150 | .2224 | .150-.213 | .2240 | .213-.275 | .2256 | .275-.350 | .2273 |
All dimensions in millimeters| Application | Light | Medium-Light | Medium-Heavy | Full Strength | Extra Strength |
| ThreadEngagement Percentage | 90% | 85% | 80% | 75% | 70% |
| Thread | MaterialThickness | HoleDiameter | MaterialThickness | HoleDiameter | MaterialThickness | HoleDiameter | MaterialThickness | HoleDiameter | MaterialThickness | HoleDiameter |
| M2 .5 x 0.45 | 0.5-0.9 | 2.24 | 0.9-1.5 | 2.25 | 1.5-2.1 | 2.27 | 2.1-2.7 | 2.28 | 2.7-3.5 | 2.30 |
| M3 x 0.5 | 0.5-1.1 | 2.71 | 1.1-1.7 | 2.72 | 1.7-2.7 | 2.74 | 2.7-3.3 | 2.76 | 3.3-4.0 | 2.77 |
| M3.5 x 0.6 | 0.6-1.4 | 3.15 | 1.4-2.0 | 3.17 | 2.0-2.9 | 3.19 | 2.9-3.8 | 3.21 | 3.8-4.5 | 3.23 |
| M4 x 0.7 | 0.8-1.4 | 3.59 | 1.4-2.4 | 3.61 | 2.4-3.3 | 3.64 | 3.3-4.4 | 3.66 | 4.4-5.5 | 3.68 |
| M5 x 0.8 | 1.0-2.1 | 4.53 | 2.1-2.9 | 4.56 | 2.9-4.4 | 4.58 | 4.4-5.9 | 4.61 | 5.9-7.1 | 4.64 |
| M6 x 1 | 1.2-2.4 | 5.42 | 2.4-3.6 | 5.45 | 3.6-4.9 | 5.48 | 4.9-6.9 | 5.51 | 6.9-8.1 | 5.55 |
(1) Hole diameters are based on a calculation of .6495 x thread pitch x % thread engagement. PENCOM strongly recommends testing in the application to determine actual working dimensions.Performance Data for Cold-Rolled Steel Sheets and Plates
All dimensions in inches unless noted| Thread | MaterialThickness | HoleDiameter | NearestDrill Size | ThreadFormingTorque(in-lbs) | Prevailing FirstRemovalTorque(in-lbs) | Rec.AssemblyTorque(in-lbs) | FailureTorque(in-lbs) |
| 2-56 | .0469 | .075 | 1.9mm | 1-2 | .5-1 | 4 | 6-73 |
| .0625 | .076 | #48 | 1.2 | .5-1 | 4 | 8-103 |
| .0938 | .079 | #47 | 1.2 | .5-1 | 5 | 11-144 |
| 4-40 | .0312 | .098 | #40 | 2-3 | 1-2 | 6 | 8-113 |
| .0625 | .102 | 2.6mm | 3-4 | 1-2 | 9 | 15-183 |
| .0938 | .102 | 2.6mm | 3-4 | 1-2 | 11 | 22-27 4 |
| 6-32 | .0625 | .120 | #31 | 4-7 | 3-4 | 14 | 25-30 3 |
| .0938 | .120 | #31 | 6-9 | 3-5 | 20 | 35-45 5 |
| .1250 | .125 | 1/8 | 6-9 | 4-6 | 22 | 39-45 4 |
| 8-32 | .0938 | .147 | #26 | 10-13 | 5-7 | 30 | 65-75 3 |
| .1250 | .150 | 3.8mm | 11-14 | 4-7 | 45 | 75-85 5 |
| .1875 | .150 | 3.8mm | 16-20 | 8-11 | 45 | 75-95 4 |
| 10-24 | .0938 | .172 | 11/64 | 14-18 | 5-8 | 35 | 65-80 3 |
| .1250 | .172 | 11/64 | 14-18 | 5-8 | 45 | 80-90 3 |
| .1875 | .172 | 11/64 | 17-22 | 9-13 | 55 | 110-115 4 |
| 10-32 | .0938 | .173 | #17 | 11-14 | 9-13 | 35 | 80-95 3 |
| .1250 | .177 | #16 | 12-16 | 9-13 | 50 | 110-120 3 |
| .1875 | .177 | #16 | 19-25 | 12-16 | 70 | 115-140 3 |
| 12-24 | .1250 | .196 | #9 | 19-24 | 9-12 | 65 | 95-115 3 |
| .1875 | .199 | #8 | 21-26 | 9-13 | 75 | 135-155 3 |
| .2500 | .203 | 13/64 | 21-26 | 10-14 | 85 | 150-170 4 |
| 1/4-20 | .1250 | .224 | 5.7mm | 30-36 | 18-25 | 85 | 170-195 3 |
| .1875 | .224 | 5.7mm | 45-55 | 25-35 | 125 | 205-235 4 |
| .2500 | .228 | #1 | 55-65 | 25-35 | 125 | 205-235 4 |
- Values determined under laboratory conditions using carbon steel hex washer head screws zinc plated and wax coated driven into cold-rolled steel members at low speeds. PENCOM strongly recommends testing in the application to determine actual working performance values.
- Recommended assembly torques represent approximately 30-50ksi clamping pressure.
- Failure most likely a result of threads stripping.
- Failure most likely a result of screw breakage.
- Failure most likely a result of threads stripping or screw breaking.
Performance Data for Cold-Rolled Steel Sheets and Plates (Cont.)
All dimensions in millimeters unless noted| Thread | MaterialThickness | HoleDiameter | NearestDrill Size | ThreadFormingTorque(N-m) | Prevailing FirstRemovalTorque(N-m) | Rec.AssemblyTorque(N-m) | FailureTorque(N-m) |
| M3 x 0.5 | 1.0 | 2.71 | #36 | 0.30-0.45 | 0.15-0.30 | 1.0 | 1.5-2.0 3 |
| 2.0 | 2.75 | 2.75mm | 0.35-0.55 | 0.15-0.30 | 1.0 | 1.6-2.5 3 |
| 3.0 | 2.75 | 2.75mm | 0.50-0.80 | 0.25-0.40 | 1.6 | 2.5-3.5 5 |
| M4 x 0.7 | 2.0 | 3.60 | 3.6mm | 0.60-0.85 | 0.30-0.40 | 1.8 | 2.8-3.8 3 |
| 3.0 | 3.66 | #27 | 0.90-1.3 | 0.50-0.70 | 3.3 | 5.5-7.5 5 |
| 4.0 | 3.66 | #27 | 1.2-1.6 | 0.60-0.85 | 4.3 | 7.0-10 5 |
| M5 x 0.8 | 2.5 | 4.57 | #15 | 1.3-2.0 | 0.60-0.80 | 2.8 | 5.3-8.0 3 |
| 3.5 | 4.57 | #15 | 1.5-2.7 | 0.90-1.5 | 6.0 | 10-12 3 |
| 5.0 | 4.60 | 4.6mm | 2.0-3.0 | 0.90-1.5 | 7.0 | 11-14 5 |
| M6 x 1 | 3.0 | 5.41 | #3 | 2.0-2.8 | 0.60-1.2 | 5.0 | 9.0-13 3 |
| 4.5 | 5.50 | 5.5mm | 3.2-4.5 | 0.90-1.5 | 10.0 | 16-21 3 |
| 6.0 | 5.50 | 5.5mm | 3.5-4.8 | 1.0-1.7 | 10.0 | 18-25 5 |
- Values determined under laboratory conditions using carbon steel hex washer head screws zinc plated and wax coated driven into cold-rolled steel members at low speeds. PENCOM strongly recommends testing in the application to determine actual working performance values.
- Recommended assembly torques represent approximately 207-345MPa clamping pressure.
- Failure most likely a result of threads stripping.
- Failure most likely a result of screw breakage.
- Failure most likely a result of threads stripping or screw breaking.
Recommended Extruded Hole Diameters for Light-Gauge Carbon Steel
All dimensions in inches| MaterialThickness | .02 | .03 | .04 | .06 | .09 | .13 | .16 | .19 |
| Thread | Hole Diameter |
| 6-32 | .118-.120 | .118-.121 | .120 | .120-.123 | .122-.125 | — | — | — |
| 8-32 | .140-.150 | .140-.150 | .150 | .150 | .147-.150 | .148-.152 | — | — |
| 10-24 | .160-.170 | .160-.170 | .164-.167 | .165-.168 | .166-.170 | .168-.173 | — | — |
| 10-32 | .170-.172 | .170-.173 | .171-.174 | .172-.175 | .173-.176 | .174-.177 | — | — |
| 12-24 | .190 | .190 | .190-.193 | .191-.194 | .192-.196 | .193-.197 | .195-.200 | .198-.203 |
| MaterialThickness | .04 | .06 | .09 | .13 | .16 | .19 | .22 | .25 |
| Thread | Hole Diameter |
| 1/4-20 | .218-.220 | .218-.221 | .219-.223 | .221-.225 | .224-.228 | .227-.231 | .228-.233 | .230-.235 |
(1) Dimensions are suggestions only. PENCOM strongly recommends testing in the application to determine actual working dimensions.Recommended Extruded Hole Diameters for Light-Gauge Carbon Steel (Cont.)
All dimensions in millimeters| MaterialThickness | 0.5 | 0.8 | 1.1 | 1.6 | 2.4 | 3.6 | 4.4 |
| Thread | Hole Diameter |
| M2.5 x 0.45 | 2.21-2.24 | 2.22-2.26 | 2.25-2.28 | 2.27-2.30 | — | — | — |
| M3 x 0.5 | 2.68-2.71 | 2.71-2.74 | 2.74-2.77 | 2.77-2.80 | 2.80-2.83 | — | — |
| M3.5 x 0.6 | 3.11-3.15 | 3.13-3.18 | 3.16-3.21 | 3.19-3.24 | 3.24-3.29 | 3.27-3.32 | — |
| M4 x 0.7 | — | 3.55-3.59 | 3.58-3.62 | 3.60-3.65 | 3.64-3.68 | 3.69-3.73 | — |
| M5 x 0.8 | — | — | 4.48-4.53 | 4.51-4.56 | 4.54-4.59 | 4.57-4.62 | — |
| M6 x 1 | — | — | 5.35-5.42 | 5.38-5.45 | 5.41-5.48 | 5.44-5.51 | 5.49-5.56 |
(1) Dimensions are suggestions only. PENCOM strongly recommends testing in the application to determine actual working dimensions.Recommended Dimensions for Extruded Light-Gauge Carbon Steel
All dimensions in inches| HoleDiameter | Material Thickness T |
| .024-.035 | .042-.048 | .060 | .090 | .106 | .122 |
| H | R | H | R | H | R | H | R | H | R | H | R |
| .081-.100 | .040 | .005 | .040 | .005 | .040 | .006 | .043 | .010 | — | — | — | — |
| .101-.130 | .047 | .005 | .047 | .005 | .047 | .006 | .052 | .010 | .054 | .010 | — | — |
| .131-.150 | .053 | .005 | .053 | .005 | .053 | .006 | .060 | .010 | .063 | .010 | .072 | .013 |
| .151-.180 | — | — | .060 | .005 | .081 | .006 | .070 | .010 | .075 | .010 | .087 | .013 |
| .181-.220 | — | — | .070 | .005 | .070 | .006 | .090 | .010 | .095 | .010 | .104 | .013 |
| .221-.260 | — | — | — | — | .075 | .006 | .100 | .010 | .105 | .010 | .120 | .013 |
| .261-.300 | — | — | — | — | .083 | .006 | .116 | .010 | .125 | .010 | .140 | .013 |
| .301-.340 | — | — | — | — | — | — | .130 | .010 | .140 | .010 | .164 | .013 |
| .341-.380 | — | — | — | — | — | — | .140 | .010 | .155 | .010 | .170 | .013 |
| .381-.430 | — | — | — | — | — | — | .150 | .010 | .170 | .010 | .184 | .013 |
All dimensions in millimeters| HoleDiameter | Material Thickness T |
| 0.61-0.89 | 1.07-1.22 | 1.52 | 2.29 | 2.69 | 3.10 |
| H | R | H | R | H | R | H | R | H | R | H | R |
| 2.06-2.54 | 1.02 | 0.13 | 1.02 | 0.13 | 1.02 | 0.15 | 1.09 | 0.25 | — | — | — | — |
| 2.57-3.30 | 1.19 | 0.13 | 1.19 | 0.13 | 1.19 | 0.15 | 1.32 | 0.25 | 1.37 | 0.25 | — | — |
| 3.33-3.81 | 1.35 | 0.13 | 1.35 | 0.13 | 1.35 | 0.15 | 1.52 | 0.25 | 1.60 | 0.25 | 1.83 | 0.33 |
| 3.84-4.57 | — | — | 1.52 | 0.13 | 1.55 | 0.15 | 1.78 | 0.25 | 1.91 | 0.25 | 2.21 | 0.33 |
| 4.60-5.59 | — | — | 1.78 | 0.13 | 1.78 | 0.15 | 2.29 | 0.25 | 2.41 | 0.25 | 2.64 | 0.33 |
| 5.61-6.60 | — | — | — | — | 1.91 | 0.15 | 2.54 | 0.25 | 2.67 | 0.25 | 3.05 | 0.33 |
| 6.63-7.62 | — | — | — | — | 2.11 | 0.15 | 2.95 | 0.25 | 3.18 | 0.25 | 3.58 | 0.33 |
| 7.65-8.64 | — | — | — | — | — | — | 3.30 | 0.25 | 3.56 | 0.25 | 3.91 | 0.33 |
| 8.66-9.65 | — | — | — | — | — | — | 3.56 | 0.25 | 3.94 | 0.25 | 4.32 | 0.33 |
| 9.68-10.92 | — | — | — | — | — | — | 3.81 | 0.25 | 4.32 | 0.25 | 4.67 | 0.33 |
(1) Dimensions are suggestions only. PENCOM strongly recommends testing in the application to determine actual working dimensions.Recommended Dimensions for Extruded Light-Gauge Carbon Steel (Cont.)Recommended Hole Dimensions for Aluminum and Zinc Die-Castings
All dimensions in inches| Thread | Cast HoleDiameter 1 | CastBossDiameterC Min. | DrilledHoleDiameterD 1 | EdgeDistanceW Min. | ThreadEngagement LengthL Min. |
| A | B |
| 2-56 | .078-.081 | .074-.077 | .197 | .0779 | .046 | .172 |
| 4-40 | .102-.105 | .096-.099 | .220 | .1006 | .065 | .224 |
| 6-32 | .125-.128 | .119-.122 | .242 | .1238 | .081 | .276 |
| 8-32 | .152-.155 | .145-.148 | .272 | .1498 | .081 | .328 |
| 10-24 | .174-.177 | .165-.168 | .315 | .1710 | .108 | .380 |
| 10-32 | .179-.182 | .171-.174 | .315 | .1758 | .081 | .380 |
| 12-24 | .200-.203 | .191-.194 | .359 | .1970 | .108 | .432 |
| 1/4-20 | .232-.235 | .221-.224 | .415 | .2273 | .130 | .500 |
All dimensions in millimeters| Thread | Cast HoleDiameter 1 | CastBossDiameterC Min. | DrilledHoleDiameterD 1 | EdgeDistanceW Min. | ThreadEngagement LengthL Min. |
| A | B |
| M2 x 0.4 | 1.83-1.91 | 1.73-1.81 | 3.32 | 1.82 | 1.00 | 4.00 |
| M2.5 x 0.45 | 2.31-2.39 | 2.20-2.28 | 4.15 | 2.29 | 1.20 | 5.00 |
| M3 x 0.5 | 2.82-2.90 | 2.68-2.76 | 4.98 | 2.77 | 1.30 | 6.00 |
| M3.5 x 0.6 | 3.23-3.31 | 3.13-3.21 | 5.81 | 3.23 | 1.60 | 7.00 |
| M4 x 0.7 | 3.74-3.82 | 3.56-3.64 | 6.64 | 3.68 | 1.80 | 8.00 |
| M5 x 0.8 | 4.72-4.80 | 4.50-4.58 | 8.30 | 4.64 | 2.10 | 10.00 |
| M6 x 1 | 5.66-5.74 | 5.40-5.48 | 9.96 | 5.54 | 2.60 | 12.00 |
- Hole diameters provide approximately 65% to 75% of thread engagement.
- Dimensions are suggestions only. PENCOM strongly recommends testing in the application to determine actual working dimensions.
TA Thread-rolling screws are available in a variety of head styles, drives, lengths, materials and finishes. Custom configurations such as SEMS washers, dog points and partially threaded shanks for “captive” applications are possible as well. Speak with a PENCOM Account Manager to learn more.
