Banc-Lok
Advantages
PSM Banc-Lok inserts are press-in expansion inserts engineered for use in hard thermosetting plastics. Their design helps create strong, serviceable threaded holes without requiring tapping or bringing excessive stress into the plastic. Banc-Lok® Inserts are especially useful when working with brittle materials where traditional knurled inserts might crack or damage the substrate.
- Easy press-in insertion
- Self-locking action on the screw - ideal where vibration is present
- Suitable for most thermosetting plastics
Key Features & Strengths
- Diamond knurl pattern: The external surface has a diamond-knurled design that allows the insert to bite into the plastic with minimal penetration into the sidewalls.
- Minimizes stress: Because the knurl only lightly penetrates the surrounding plastic, radial stress (bursting forces) is reduced, mitigating risk of cracking or damage.
- Self-locking action: The insert provides inherent locking on the screw, improving resistance under vibration and creep.
- Easy press-in installation: BANC-LOK inserts can be installed via a simple press without special or complex tooling.
- Good pull-out resistance: Despite minimal sidewall engagement, the design delivers reliable retention strength.
- Suitable for many thermosetting plastics: They’re optimized for materials that are harder or more brittle, where traditional knurled inserts may struggle.
Selection of Inserts
ISO Metric
| PRODUCT CODE | THREAD SIZE | INSERT LENGTH A | PREFERRED OTHER LENGTH A | HEAD HEIGHT B | HEAD Ø C | INSERT Ø D | REC. HOLE SIZE -0.00 +0.10 | MIN. WALL THICKNESS |
|---|---|---|---|---|---|---|---|---|
|
N41-B N42-B N42R-B | M2 | 3.9 | - | 0.43 | 4.8 | 3.2 | 3.2 | 2.4 |
| M2.5 | 4.7 | - | 0.51 | 5.5 | 4.0 | 4.0 | 3.2 | |
| M3 | 4.7 | 3.5 | 0.51 | 5.5 | 4.0 | 4.0 | 3.2 | |
| M3.5 | 6.3 | 3.5 | 0.66 | 6.4 | 4.7 | 4.8 | 3.6 | |
| M4 | 7.9 | 5.0 | 0.82 | 7.1 | 5.5 | 5.6 | 4.0 | |
| M5 | 9.4 | 6.0 | 0.99 | 7.9 | 6.3 | 6.4 | 4.8 | |
| M6 | 12.6 | 9.5 | 1.25 | 9.5 | 7.9 | 8.0 | 6.0 | |
| M8 | 12.6 | 9.5 | 1.25 | 11.1 | 9.5 | 9.6 | 7.0 |
Other lengths possible on quotation.
Unified
| PRODUCT CODE | THREAD SIZE | INSERT LENGTH A | PREFERRED OTHER LENGTH A | HEAD HEIGHT B | HEAD Ø C | INSERT Ø D | REC. HOLE SIZE -0.000 +0.004 | MIN. WALL THICKNESS |
|---|---|---|---|---|---|---|---|---|
|
N41-B N42-B N42R-B | 2-56 | .155 | - | .017 | .187 | .124 | .126 | .094 |
| 4-40 | .186 | .138 | .020 | .218 | .156 | .157 | .126 | |
| 6-32 | .249 | .138 | .026 | .250 | .186 | .189 | .142 | |
| 8-32 | .312 | .197 | .032 | .281 | .217 | .220 | .157 | |
| 10-24 | .371 | .236 | .039 | .312 | .249 | .252 | .189 | |
| 10-32 | .371 | .236 | .039 | .312 | .249 | .252 | .189 | |
| 1/4-20 | .497 | .374 | .049 | .375 | .311 | .315 | .236 | |
| 1/4-28 | .497 | .374 | .049 | .375 | .311 | .315 | .236 | |
| 5/16-18 | .497 | .374 | .049 | .437 | .374 | .378 | .276 | |
| 5/16-24 | .497 | .374 | .049 | .437 | .374 | .378 | .276 |
Other materials and lenghts 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. The top of the hole should not be chamfered or counterbored and care must be taken to avoid bell mouthing. Drilled holes may be used but performance may be reduced when compared with a molded hole. Hole diameter tolerance: -0.00 +0.10mm.
Selection of Insert Type
Headed inserts may be used for improved electrical contact or to fill gaps which would result in a jack-out condition. Alternatively a reverse headed type may be used with the head on the back of the molding. This head then gives extra support for resistance to jack-out loads. These inserts are not recommended for use in thermosetting polyesters with high filler content (DMC, SMC, BMC), for applications using these materials we recommended Screw-Sert.
Influence of Screw Dimensions
It is important that the fixing screw fully penetrates the insert in order to achieve full expansion. Screw length should therefore be calculated to ensure that this condition is met before the final clamp torque is applied.
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 show the relative performance of the inserts in the range.
Enhance Your Assembly with Our Precision Banc-Lok Inserts
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