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Sonic-Lok
PSM SONIC-LOK inserts are engineered for rapid installation into thermoplastic materials using heat or ultrasonic energy. They combine ease and speed of insertion with strong mechanical performance. Their geometry includes opposed helical knurl bands to deliver a balance of high torque resistance and pull-out strength. They’re available in captive and flanged versions, as well as stud types, making them versatile for many plastic fastening needs.
Advantages
- Permits thin boss walls allowing compact boss design
- Provides high torque and pull out performance
- Rapid installation using heat or ultrasonic
- Choice of lengths available
- Self-aligning – Assists Installation
Selection of Sonic-Lok Inserts
ISO Metric
| PRODUCT CODE | THREAD SIZE | INSERT LENGTH A | PREFERRED SHORTER LENGTHS A | STUD LENGTHS (FOR SLTS & SLHS ONLY) S | HEAD HEIGHT B | HEAD Ø C | INSERT Ø D | PILOT END Ø P | REC. HOLE SIZE -0.00 +0.10 | MIN. WALL THICKNESS | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 25 | ||||||||||||
| SL-B SHK-B SLTS-B SLHS-B | M2 | 4.0 | 2.5 | 3.0 | - | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 25 | 0.53 | 4.8 | 3.6 | 3.1 | 3.2 | 1.3 |
| M2.5 | 5.7 | 4.0 | - | - | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 25 | 0.61 | 5.5 | 4.6 | 3.9 | 4.0 | 1.6 | |
| M3 | 5.7 | 4.0 | 4.8 | - | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 25 | 0.61 | 5.5 | 4.6 | 3.9 | 4.0 | 1.6 | |
| M3.5 | 7.1 | 5.0 | - | - | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 25 | 0.76 | 6.4 | 5.4 | 4.7 | 4.8 | 1.8 | |
| M4 | 8.1 | 4.0 | 4.8 | 5.8 | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 25 | 0.91 | 7.1 | 6.3 | 5.5 | 5.6 | 2.1 | |
| M5 | 9.5 | 5.8 | - | - | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 25 | 1.09 | 7.9 | 7.1 | 6.3 | 6.4 | 2.16 | |
| M6 | 12.7 | 6.8 | 9.5 | - | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 25 | 1.35 | 9.5 | 8.7 | 7.9 | 8.0 | 3.3 | |
| M8 | 12.7 | - | - | - | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 25 | 1.35 | 11.1 | 10.2 | 9.5 | 9.6 | 4.5 | |
| M10 | 12.7 | - | - | - | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 25 | 1.60 | 14.0 | 12.6 | 11.8 | 11.9 | 6.0 | |
| M12 | 15.9 | - | - | - | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 25 | 2.00 | 19.0 | 16.7 | 15.8 | 16.0 | 8.0 | |
PRODUCT CODE
SL-BSHK-BSLTS-BSLHS-B
THREAD SIZEM2
Insert LengthA4.0
Head HeightB0.53
Head ØC4.8
Insert ØD3.6
Pilot End ØP3.1
Rec. Hole Size-0.00 / +0.103.2
Min. Wall Thickness1.3
Preferred Shorter Lengths A
2.53.0-
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
55
66
88
1010
1212
1414
1616
1818
2020
2525
THREAD SIZEM2.5
Insert LengthA5.7
Head HeightB0.61
Head ØC5.5
Insert ØD4.6
Pilot End ØP3.9
Rec. Hole Size-0.00 / +0.104.0
Min. Wall Thickness1.6
Preferred Shorter Lengths A
4.0--
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
55
66
88
1010
1212
1414
1616
1818
2020
2525
THREAD SIZEM3
Insert LengthA5.7
Head HeightB0.61
Head ØC5.5
Insert ØD4.6
Pilot End ØP3.9
Rec. Hole Size-0.00 / +0.104.0
Min. Wall Thickness1.6
Preferred Shorter Lengths A
4.04.8-
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
55
66
88
1010
1212
1414
1616
1818
2020
2525
THREAD SIZEM3.5
Insert LengthA7.1
Head HeightB0.76
Head ØC6.4
Insert ØD5.4
Pilot End ØP4.7
Rec. Hole Size-0.00 / +0.104.8
Min. Wall Thickness1.8
Preferred Shorter Lengths A
5.0--
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
55
66
88
1010
1212
1414
1616
1818
2020
2525
THREAD SIZEM4
Insert LengthA8.1
Head HeightB0.91
Head ØC7.1
Insert ØD6.3
Pilot End ØP5.5
Rec. Hole Size-0.00 / +0.105.6
Min. Wall Thickness2.1
Preferred Shorter Lengths A
4.04.85.8
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
55
66
88
1010
1212
1414
1616
1818
2020
2525
THREAD SIZEM5
Insert LengthA9.5
Head HeightB1.09
Head ØC7.9
Insert ØD7.1
Pilot End ØP6.3
Rec. Hole Size-0.00 / +0.106.4
Min. Wall Thickness2.16
Preferred Shorter Lengths A
5.8--
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
55
66
88
1010
1212
1414
1616
1818
2020
2525
THREAD SIZEM6
Insert LengthA12.7
Head HeightB1.35
Head ØC9.5
Insert ØD8.7
Pilot End ØP7.9
Rec. Hole Size-0.00 / +0.108.0
Min. Wall Thickness3.3
Preferred Shorter Lengths A
6.89.5-
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
55
66
88
1010
1212
1414
1616
1818
2020
2525
THREAD SIZEM8
Insert LengthA12.7
Head HeightB1.35
Head ØC11.1
Insert ØD10.2
Pilot End ØP9.5
Rec. Hole Size-0.00 / +0.109.6
Min. Wall Thickness4.5
Preferred Shorter Lengths A
---
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
55
66
88
1010
1212
1414
1616
1818
2020
2525
THREAD SIZEM10
Insert LengthA12.7
Head HeightB1.60
Head ØC14.0
Insert ØD12.6
Pilot End ØP11.8
Rec. Hole Size-0.00 / +0.1011.9
Min. Wall Thickness6.0
Preferred Shorter Lengths A
---
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
55
66
88
1010
1212
1414
1616
1818
2020
2525
THREAD SIZEM12
Insert LengthA15.9
Head HeightB2.00
Head ØC19.0
Insert ØD16.7
Pilot End ØP15.8
Rec. Hole Size-0.00 / +0.1016.0
Min. Wall Thickness8.0
Preferred Shorter Lengths A
---
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
55
66
88
1010
1212
1414
1616
1818
2020
2525
Other lengths possible on quotation.
Unified
| PRODUCT CODE | THREAD SIZE | INSERT LENGTH A | PREFERRED OTHER LENGTH A* | STUD LENGTHS (FOR SLTS & SLHS ONLY) S | HEAD HEIGHT B | HEAD Ø C | INSERT Ø D | PILOT END Ø P | REC. HOLE SIZE -0.00 +0.004 | MIN. WALL THICKNESS | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | |||||||||||||
|
SL-B SHK-B SLTS-B SLHS-B | 0-80 | .125 | - | - | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | - | - | .116 | .095 | .100 | .051 |
| 2-56 | .157 | .100 | .125 | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .021 | .187 | .141 | .123 | .126 | .051 | |
| 4-40 | .226 | .096 | .140 | .170 | .250 | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .024 | .218 | .181 | .154 | .157 | .063 | |
| 6-32 | .281 | .150 | .226 | .250 | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .030 | .250 | .214 | .185 | .189 | .071 | |
| 8-32 | .321 | .185 | .250 | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .036 | .281 | .248 | .218 | .220 | .083 | |
| 10-24 | .375 | .250 | - | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .043 | .312 | .278 | .249 | .252 | .102 | |
| 10-32 | .375 | .226 | .250 | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .043 | .312 | .278 | .249 | .252 | .102 | |
| 1/4-20 | .500 | .250 | - | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .053 | .375 | .341 | .312 | .315 | .130 | |
| 1/4-28 | .500 | - | - | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .053 | .375 | .341 | .312 | .315 | .130 | |
| 5/16-18 | .500 | - | - | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .053 | .437 | .403 | .374 | .378 | .177 | |
| 5/16-24 | .500 | - | - | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .053 | .437 | .403 | .374 | .378 | .177 | |
| 3/8-16 | .500 | - | - | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .063 | .551 | .494 | .465 | .469 | .236 | |
| 3/8-24 | .500 | - | - | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .063 | .551 | .494 | .465 | .469 | .236 | |
| 1/8-NPT | .625 | - | - | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | - | - | .479 | .450 | .453 | .236 | |
| 1/2 | .625 | - | - | - | - | 3/16 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | .079 | .748 | .657 | .622 | .630 | .315 | |
PRODUCT CODE
SL-BSHK-BSLTS-BSLHS-B
THREAD SIZE0-80
Insert LengthA.125
Head HeightB-
Head ØC-
Insert ØD.116
Pilot End ØP.095
Rec. Hole Size-0.00 / +0.004.100
Min. Wall Thickness.051
Preferred Other Length A*
----
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE2-56
Insert LengthA.157
Head HeightB.021
Head ØC.187
Insert ØD.141
Pilot End ØP.123
Rec. Hole Size-0.00 / +0.004.126
Min. Wall Thickness.051
Preferred Other Length A*
.100.125--
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE4-40
Insert LengthA.226
Head HeightB.024
Head ØC.218
Insert ØD.181
Pilot End ØP.154
Rec. Hole Size-0.00 / +0.004.157
Min. Wall Thickness.063
Preferred Other Length A*
.096.140.170.250
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE6-32
Insert LengthA.281
Head HeightB.030
Head ØC.250
Insert ØD.214
Pilot End ØP.185
Rec. Hole Size-0.00 / +0.004.189
Min. Wall Thickness.071
Preferred Other Length A*
.150.226.250-
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE8-32
Insert LengthA.321
Head HeightB.036
Head ØC.281
Insert ØD.248
Pilot End ØP.218
Rec. Hole Size-0.00 / +0.004.220
Min. Wall Thickness.083
Preferred Other Length A*
.185.250--
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE10-24
Insert LengthA.375
Head HeightB.043
Head ØC.312
Insert ØD.278
Pilot End ØP.249
Rec. Hole Size-0.00 / +0.004.252
Min. Wall Thickness.102
Preferred Other Length A*
.250---
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE10-32
Insert LengthA.375
Head HeightB.043
Head ØC.312
Insert ØD.278
Pilot End ØP.249
Rec. Hole Size-0.00 / +0.004.252
Min. Wall Thickness.102
Preferred Other Length A*
.226.250--
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE1/4-20
Insert LengthA.500
Head HeightB.053
Head ØC.375
Insert ØD.341
Pilot End ØP.312
Rec. Hole Size-0.00 / +0.004.315
Min. Wall Thickness.130
Preferred Other Length A*
.250---
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE1/4-28
Insert LengthA.500
Head HeightB.053
Head ØC.375
Insert ØD.341
Pilot End ØP.312
Rec. Hole Size-0.00 / +0.004.315
Min. Wall Thickness.130
Preferred Other Length A*
----
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE5/16-18
Insert LengthA.500
Head HeightB.053
Head ØC.437
Insert ØD.403
Pilot End ØP.374
Rec. Hole Size-0.00 / +0.004.378
Min. Wall Thickness.177
Preferred Other Length A*
----
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE5/16-24
Insert LengthA.500
Head HeightB.053
Head ØC.437
Insert ØD.403
Pilot End ØP.374
Rec. Hole Size-0.00 / +0.004.378
Min. Wall Thickness.177
Preferred Other Length A*
----
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE3/8-16
Insert LengthA.500
Head HeightB.063
Head ØC.551
Insert ØD.494
Pilot End ØP.465
Rec. Hole Size-0.00 / +0.004.469
Min. Wall Thickness.236
Preferred Other Length A*
----
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE3/8-24
Insert LengthA.500
Head HeightB.063
Head ØC.551
Insert ØD.494
Pilot End ØP.465
Rec. Hole Size-0.00 / +0.004.469
Min. Wall Thickness.236
Preferred Other Length A*
----
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE1/8-NPT
Insert LengthA.625
Head HeightB-
Head ØC-
Insert ØD.479
Pilot End ØP.450
Rec. Hole Size-0.00 / +0.004.453
Min. Wall Thickness.236
Preferred Other Length A*
----
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
THREAD SIZE1/2
Insert LengthA.625
Head HeightB.079
Head ØC.748
Insert ØD.657
Pilot End ØP.622
Rec. Hole Size-0.00 / +0.004.630
Min. Wall Thickness.315
Preferred Other Length A*
----
STUD LENGTHS (FOR SLTS & SLHS ONLY) S
3/163/16
1/41/4
5/165/16
3/83/8
7/167/16
1/21/2
5/85/8
3/43/4
7/87/8
11
STANDARD MATERIAL: BRASS (B) Other materials and lengths possible on quotation.
Specifying an Insert
Boss Design Specification
Hole Preparation
Molded holes are recommended wherever possible. The taper on a molded hole should be 1° inclusive and the hole diameter recommended should apply at the point reached by the bottom of the insert. Drilled holes may be used but performance may be reduced when compared with a molded hole. The top of the hole should not be chamfered or counterbored and care must be taken to avoid bell mouthing. Hole diameter tolerance: •0.00 •0.10mm.
Installation
The fastener may be installed using either a pre-heating process or using heat generated by ultrasonic vibrations. Where preheating is used, care must be exercised to ensure that the fastener softens but does not melt the plastic. This will avoid any tendency to generate unsightly “flash” around the top of the insert. Ultrasonic installation is best carried out using low amplitude vibration and the minimum power consistent with satisfactory softening of the plastic material. In either case excessive pressure should be avoided, since this may result in the insert being forced into the hole without allowing the plastic to soften and flow around the surface profile.
Wall Thickness
A general guide to minimum wall thickness is given in the data table but this will vary depending upon the nature of the plastic. Where thinner walls are required these can often be accommodated, but consultation with the P.S.M Technology Centre or local sales office and pre-production testing is strongly advised.
Performance Data
The complexity of materials and variations in service conditions make it impossible to detail fastener performance for specific applications. The chart below gives a general guide and shows the relative performance of the inserts in the range.
Enhance Your Assembly with Our Precision Sonic-Lok Inserts
Start browsing our products or request a quote today to find the ideal fastening solution for your application.Frequently Asked Questions About Sonic-Lok Inserts
What is a Sonic-Lok Insert?
Sonic-Lok Inserts (SL/SHK/SLTS/SLHS) is a brass threaded insert for plastic parts, engineered for rapid installation into thermoplastic materials using either heat or ultrasonic energy. This dual compatibility gives manufacturers flexibility to use whichever method best suits their existing equipment, production volume, and plastic material type.
Can Sonic-Lok Inserts be installed with both heat and ultrasonic methods?
Yes. Sonic-Lok Inserts are specifically engineered to support both heat-staking and ultrasonic insertion as installation methods. This is a key advantage over insert designs optimised for only one method, since it allows the same insert part number to be used across different production lines or facilities regardless of which installation equipment is available.
What is the difference between heat and ultrasonic installation for Sonic-Lok Inserts?
Heat installation uses a heated tip or soldering-iron-style tool to soften the plastic around the insert as it is pressed in, suited to lower-volume or manual production. Ultrasonic installation uses high-frequency vibration to generate localised frictional heat, enabling faster cycle times suited to automated, high-volume production. Sonic-Lok Inserts are designed to perform reliably with either method.
What is the difference between SL, SHK, SLTS, and SLHS Sonic-Lok variants?
SL, SHK, SLTS, and SLHS are variants within PSM’s Sonic-Lok range, differing in head/flange style, length, and thread specification to suit different boss designs and installation requirements. All variants share the same brass construction and dual heat/ultrasonic installation capability. PSM’s dimensional data sheet specifies the exact distinguishing features of each code.
What plastic materials are compatible with Sonic-Lok Inserts?
Sonic-Lok Inserts are designed for common thermoplastics used in heat-staking and ultrasonic insertion applications, including ABS, polycarbonate, nylon (PA), and acetal (POM). The dual installation method compatibility makes Sonic-Lok Inserts a flexible choice across a wide range of thermoplastic part designs and production environments.