Services  ·  Lasertech Metal Works

Fastener Insertion

Permanent, flush, load-bearing threads pressed directly into sheet metal — without welding, without tapping thin material, without a second vendor. PEM self-clinching hardware is the industry-standard solution for adding strong, reusable threaded attachment points to panels, enclosures, brackets, and assemblies in any gauge of steel, stainless, or aluminum.

Fastener Insertion Image
PEMSelf-Clinching Hardware
4 TypesNuts · Studs · Standoffs · CPS
In-HouseIn-Sequence with Fabrication
Inch + MetricAll Standard Thread Sizes

The Clinching
Action.

PEM self-clinching fasteners work by a cold-forming process — not by welding, adhesive, or thread engagement alone. When the press applies force, the fastener's undercut geometry causes the parent metal to flow into and around the clinching groove, permanently locking the fastener in place. The result is a connection that transfers load through the metal itself, not through friction or clamping.

Installation requires only a precisely sized hole and a press capable of delivering the correct force. No heat, no chips, no secondary cleaning. The fastener sits flush with one face of the panel — often completely invisible from the finished side after powder coating.

1

Punch or Drill the Mounting Hole

Each PEM hardware type and size requires a specific hole diameter — called the mounting hole. The hole must be within the tolerance published by PEM to produce a proper clinch: too small and the fastener won't seat; too large and the clinch won't engage. At Lasertech, mounting holes are punched by the laser-punch combo machine or laser-cut to the correct diameter as part of the flat pattern program — no additional drilling required.

2

Locate the Fastener in the Hole

The fastener is placed shank-down into the mounting hole from the correct side — the clinch flange rests on the panel surface. Correct orientation is critical: clinch nuts are pressed flush on the installation side; studs press from the non-thread side. Hardware is positioned with the anvil tooling below supporting the panel.

3

Press to Specified Force

The press ram applies a controlled squeezing force between the punch and anvil tooling — typically 400 to 1,000 lbf depending on fastener size and material. This force plastically deforms the parent metal into the fastener's clinching groove. The deformation is irreversible — the fastener cannot be removed without damaging the panel.

4

Inspect and Verify

Installed fasteners are checked for flush seating (no protrusion above panel surface on the clinch side), proper clinch groove engagement (no gap between flange and panel), and torque resistance (spinning torque not present — a properly installed clinch nut cannot rotate). The fastener is then ready for powder coating, assembly, and final use.

Strong Threads
in Thin Metal.

Thin sheet metal — the material that makes up most enclosures, panels, brackets, and covers — is too thin for reliable tapping. PEM self-clinching hardware was engineered specifically to solve this problem, and it has become the standard solution across industries wherever thin-sheet threaded connections are required.

Full Thread Engagement in Any Thickness

A PEM clinch nut provides the same thread depth regardless of panel thickness — the nut body extends through the panel and presents its full thread length to the fastener. A 16-gauge steel panel gets the same thread engagement as a 3/16″ panel. Tapping that same 16-gauge panel would yield fewer than two usable threads.

Flush Installation — No Protrusion

Clinch nuts, studs, and standoffs are designed to sit flush with or below the panel surface on the installation side. No raised boss, no weld bead, no protruding hardware. The panel can lay flat against a mating surface and stack cleanly in shipping or assembly fixtures.

Vibration Resistant — Cannot Spin Out

A properly installed PEM clinch nut cannot rotate — the clinched metal locks the fastener rotationally as well as axially. Unlike a nut and bolt through a clearance hole, or a tapped thread that can strip under dynamic load, the clinch connection maintains torque resistance through thousands of assembly cycles.

No Heat, No Chips, No Cleanup

PEM insertion is a cold process — no welding distortion, no tapping chips to clean from the panel, no heat-affected zone, no weld spatter. The panel goes into the press, comes out with installed hardware, and proceeds directly to finishing and powder coating without a cleanup step.

In-Sequence at Lasertech

Hardware insertion at Lasertech is performed in-house after laser cutting and forming but before welding, finishing, and powder coating — in the correct sequence, on the same floor, without outsourcing. Coordination between cutting, hardware insertion, and masking for coating is handled internally.

Four Types of
Self-Clinching Hardware

Each type of PEM self-clinching hardware solves a different fastening problem. Choosing the right type depends on what the panel needs to do — receive a bolt, present a stud, maintain spacing, or stay closed without loose hardware.

Clinch Nuts

PEM Type S / SP / SS / CLA

A clinch nut is a self-clinching threaded insert — a nut body that is pressed permanently into a panel to provide a strong, reusable female thread. The fastener (bolt or screw) threads into the nut from the opposite side of the panel. Clinch nuts are the most common PEM hardware type and appear in virtually every application requiring a bolted connection in sheet metal.

Type S is the standard floating-pilot clinch nut for steel and stainless. Type SS is specifically designed for stainless steel panels. Type CLA is a thin-sheet clinch nut for panels too thin for the standard S series.

Receives Bolt or Screw · Flush on Install Side
Typical sizes#4-40 through 1/2-13 · M3–M12
Min panel thickness0.040″ (16 ga)
MaterialsSteel, Stainless, Aluminum
Install fromTop (access side)
PEM seriesS, SP, SS, CLA
Common finishZinc, Passivated, Plain

Clinch Studs

PEM Type FH / FHS / FHL / FHB

A clinch stud presents a permanently attached threaded post on one side of the panel. Instead of a bolt threading into the panel, hardware is mounted over the stud and secured with a nut from the outside. Studs are used when the panel must present a fixed thread for mounting PCBs, covers, brackets, and standoff assemblies where access to the back of the panel is limited or unavailable.

Type FH is the standard flush-head stud for steel. FHS for stainless panels. FHL is a long shank version for thicker panel stacks. FHB provides a blind installation option where back-side access is restricted.

Presents Fixed Thread · Mounts From One Side
Typical sizes#4-40 through 3/8-16 · M3–M10
Min panel thickness0.040″ (16 ga)
MaterialsSteel, Stainless
Install fromOpposite stud side
PEM seriesFH, FHS, FHL, FHB
Stud protrusionVaries by shank length

Standoffs

PEM Type SO / SOA / SOAH / HFE

A standoff is a self-clinching threaded hex spacer that is pressed permanently into a panel to provide a precisely controlled mounting height for a second panel, PCB, or cover. The standoff accepts a screw through the mating component on one end and its opposite face may be open (through-threaded) or closed. Used extensively in electronics enclosures, instrument panels, and anywhere PCBs must be mounted at a consistent standoff distance without loose spacers.

Type SO is a standard open-threaded standoff. SOA has an unthreaded pilot end for self-locating installation. SOAH is an extended-height version. HFE provides external threads for alternative stacking configurations.

PCB Mounting · Controlled Spacing · No Loose Parts
Typical sizes#4-40 through 1/4-20 · M3–M6
Heights available0.187″ through 1.50″
MaterialsSteel, Stainless, Aluminum
Install fromNon-board side
PEM seriesSO, SOA, SOAH, HFE
Height tolerance±0.010″ typical

Captive Panel Screws

PEM Type TRS / TFS / CPS / SMPS

A captive panel screw is a screw permanently captured in a panel — it can be turned and disengaged but cannot be fully removed or dropped. When the screw is backed out, it remains in the panel rather than falling free. This makes captive panel screws the standard choice for access panels, covers, and hatches that require frequent removal during maintenance, inspection, or service — anywhere loose fasteners create a drop hazard or housekeeping problem.

TRS and TFS are standard turnlock designs for single-turn opening. CPS uses a clinch barrel retained in the panel. SMPS is a spring-loaded version that self-retracts when disengaged for clean alignment during panel replacement.

Access Panels · No Loose Hardware · Drop Prevention
Typical sizes#6-32 through 1/4-20 · M3–M5
EngagementMating clinch nut or tapped hole
MaterialsSteel, Stainless
Drive typesPhillips, Hex, Torx, Slotted
PEM seriesTRS, TFS, CPS, SMPS
Spring versionSelf-retracting SMPS

Why the Joint
is Permanent.

Unlike a pressed-in insert that relies on friction, a PEM self-clinching fastener relies on metal displacement. The parent sheet metal is permanently deformed into the fastener's geometry — the connection is as strong as the surrounding sheet material and transfers load through the metal, not through friction or adhesion.

A

Knurled Shank Prevents Rotation

The fastener shank has a knurled, serrated, or polygonal profile that keys into the surrounding metal after installation. This prevents the fastener from rotating under applied torque — critical for clinch nuts that must remain fixed when a bolt is tightened against them.

B

Undercut Groove Prevents Axial Pullout

The clinching groove is an undercut in the fastener shank. When the press deforms the parent metal into this groove, the metal interlocks with the undercut geometry — creating a mechanical lock that resists axial pull-out loads without depending on friction alone.

C

Pilot Aids Alignment

Many PEM types include a self-locating pilot that centers the fastener in the mounting hole before the press stroke begins. This ensures concentricity between the fastener thread axis and the mounting hole center, maintaining true thread alignment in the finished panel.

D

Parent Metal Must Be Softer

Proper clinching requires the parent panel material to be softer than the fastener so that the panel deforms into the fastener — not the other way around. Standard steel, stainless, and aluminum sheet all satisfy this requirement. Hardened or heat-treated materials may not.

Mounting Hole
Sizes by Type.

Every PEM hardware type and thread size requires a specific mounting hole diameter in the parent panel. The hole must be within the published tolerance — typically ±0.003″ — to produce a proper clinch. At Lasertech, mounting holes are cut to the correct diameter as part of the flat pattern program on the laser or punch machine, eliminating a separate drilling step.

Thread Size
Clinch Nut (S)
Clinch Stud (FH)
Standoff (SO)
Inch Series
#4-40
0.166″
0.166″
0.173″
#6-32
0.193″
0.193″
0.201″
#8-32
0.213″
0.213″
0.221″
#10-32
0.243″
0.243″
0.250″
¼-20
0.281″
0.281″
0.291″
5⁄16-18
0.344″
0.344″
0.354″
⅜-16
0.406″
0.406″
0.416″
Metric Series
M3
4.2 mm
4.2 mm
4.4 mm
M4
5.4 mm
5.4 mm
5.6 mm
M5
6.2 mm
6.2 mm
6.4 mm
M6
7.4 mm
7.4 mm
7.6 mm
M8
9.6 mm
9.6 mm
9.8 mm

Holes Cut to Size at Laser — No Drilling

Lasertech programs PEM mounting hole diameters directly into the flat pattern. Holes are cut to the correct diameter on the laser or punch machine — no separate drilling operation, no operator measurement required, consistent from part to part across any production quantity.

Panel Materials
for PEM Hardware

PEM hardware can be installed in any panel material that is softer than the fastener — which includes all standard sheet metal and plate used in fabrication at Lasertech. Material hardness determines which PEM series is appropriate and what minimum panel thickness is required.

Mild Steel / Cold-Rolled Steel

The most common panel material for PEM hardware. Standard Type S clinch nuts, FH studs, and SO standoffs are all designed to install in cold-rolled or hot-rolled mild steel. Good clinch quality across the full gauge range from 28 gauge through 3/16″. PEM hardware is typically zinc-plated to match corrosion protection level of the panel before powder coating.

Type S · FH · SO · Full Gauge Range

Stainless Steel 304 / 316

Stainless panels require stainless-specific PEM series (SS for nuts, FHS for studs) — standard carbon steel fasteners can gall against stainless during installation. The SS and FHS series use materials and geometry engineered for stainless-to-stainless installation. Slightly higher installation force required due to stainless work-hardening.

Type SS · FHS · Stainless-Specific Series

Aluminum 5052 / 6061

Aluminum is the softest common panel material — it deforms readily into the clinch groove, making PEM hardware particularly effective. Aluminum panels typically use steel or stainless PEM hardware (the fastener is harder than the panel, satisfying the clinching requirement). Minimum panel thickness requirements are similar to steel by gauge, but the softer material produces excellent clinch pull-out values.

Steel / Stainless Fasteners in Aluminum Panel

Materials That Cannot Be Clinched

Hardened or heat-treated steels (above approximately 35 HRC), brittle materials, and non-metallic substrates are not suitable for PEM self-clinching hardware — the material cannot flow into the clinch groove without fracturing or failing to lock. For these applications, weld nuts, threaded inserts, or through-hole fastening must be substituted.

Hardened Steel · Brittle Materials — Not Suitable

How to Specify
PEM Hardware.

PEM hardware is specified by part number on the drawing BOM, or by a complete hardware callout as a leader note. These design requirements ensure correct installation without back-and-forth.

Design & Drawing Requirements
1
Call Out PEM Part Number or Series

Specify the PEM part number (e.g., S-832-2ZI) on the drawing BOM or as a leader note to the hole. If exact part number is unknown, specify: hardware type, thread size, material, and minimum panel thickness. Lasertech will select the correct series and size.

2
Specify the Mounting Hole Diameter

Include the PEM mounting hole diameter on the drawing as the hole callout — not the thread size. The mounting hole is different from and larger than the thread minor diameter. Use the published PEM mounting hole chart for each size and series.

3
Note Edge Distance and Spacing

PEM hardware requires minimum edge distance from the hole center to the nearest panel edge — typically 2× the mounting hole diameter. Inadequate edge distance prevents proper clinch engagement and can cause edge deformation or fastener push-through. Check PEM's published edge distance requirements for each series.

4
Mark Installation Side on Drawing

Indicate which face is the installation (clinch) side and which is the access side. Clinch nuts are installed from the access side (the side a bolt would approach); studs are installed from the opposite side. An incorrect installation side reverses the flush face and may create interference in the assembly.

5
Confirm Panel Thickness vs. Min Requirement

Each PEM series has a minimum panel thickness requirement — installing into material thinner than the minimum produces an incomplete clinch and poor pull-out resistance. Verify panel gauge against the PEM specification for the chosen series before finalizing the design.

6
Note Masking If Powder Coating

Clinch nut threads and standoff bores should be masked during powder coating to prevent thread fill. Include a note: "MASK PEM HARDWARE BEFORE POWDER COAT." Lasertech coordinates masking internally between the hardware insertion and coating teams.

Not Sure What to Specify?

Submit your drawing with material, gauge, and a description of the fastening requirement — "needs M4 tapped hole in 16ga steel panel" — and our team will recommend the correct PEM series, size, and mounting hole diameter. Call 770-461-9941 or use our contact form.

Which Type for
Your Application?

Use this matrix to match hardware type to application requirement. Multiple types can appear on the same panel — mix and match as the assembly demands.

Requirement
Clinch Nut
Clinch Stud
Standoff
Captive Screw
Receive bolt or screw from outside panel
✓ Ideal
Present threaded post on panel surface
✓ Ideal
Mount PCB or second panel at controlled height
✓ Ideal
Access panel / cover that opens frequently
✓ Ideal
Prevent dropped or lost fasteners
✓ Yes
Works in thin sheet metal (< 3/16″)
✓ Yes
✓ Yes
✓ Yes
✓ Yes
Flush on panel surface (no protrusion)
✓ Flush
✓ Flush head
✓ Flush
✓ Flush
Vibration-resistant, cannot spin
✓ Yes
✓ Yes
✓ Yes
✓ Yes
Reusable (thread side)
✓ Yes
✓ Yes
✓ Both ends
✓ Yes

Where Fastener Insertion
Fits in the Sequence

PEM hardware is typically installed after laser cutting and forming but before welding — so hardware seats cleanly on the formed panel before heat distortion occurs, and threads are accessible before welded structure closes off access to the installation press.

Laser Cut

Mounting holes cut to exact PEM diameter — programmed from the flat pattern.

Form

Press brake forming on the flat sheet before hardware insertion — hardware goes in after bending.

← INSERTION

Insert Hardware

PEM nuts, studs, standoffs, and captive screws pressed into formed panels.

Weld & Finish

Hardware-populated panels welded into assemblies. Threads masked before powder coating.

Coat & Ship

Powder coated. Masking removed. Hardware verified. Kitted and shipped.

Industries & Applications

PEM self-clinching hardware appears in every industry that uses sheet metal enclosures, panels, or structural brackets where strong threaded connections are needed in thin material.

01

Electrical Enclosures

The highest-volume PEM application. Enclosure panels, back plates, and covers use clinch nuts throughout for component mounting, DIN rail attachment, and cover fastening — in 16 gauge and 14 gauge steel where tapping is not reliable.

02

Generator & Energy

Control panels, access covers, and internal mounting brackets in generator enclosures use clinch nuts and captive panel screws — for fast, tool-accessible opening in field service conditions where loose hardware is a maintenance liability.

03

Electronics & Instrumentation

Standoffs for PCB mounting, clinch studs for grounding lugs, and captive screws on instrument covers — the three hardware types that define the standard electronics enclosure build.

04

Industrial OEM Equipment

Access panels on machine frames and guarding, cover plates on control stations, and mounting brackets for sensors and junction boxes — all using clinch hardware in formed sheet metal panels.

05

Food Service Equipment

Stainless steel panels and covers in food service equipment use SS-series stainless PEM hardware — same material system, same cleanability, no galvanic incompatibility between panel and fastener.

06

Auto Racing

Lightweight aluminum panel work — dash panels, firewall covers, and body panels — where clinch hardware provides strong threads without adding welded bosses or weld nuts that distort thin aluminum sheet.

07

HVAC & Mechanical

Unit covers, access panels, and control enclosures use captive panel screws for service accessibility and clinch nuts for component mounting in formed sheet metal housings.

08

Architectural & Display

Decorative panel systems, signage frames, and architectural metalwork use clinch hardware where visible fastening must be flush, clean, and repeatable across large panel quantities.

Frequently Asked Questions

Common questions about fastener insertion services at Lasertech Metal Works.

PEM self-clinching fasteners are threaded hardware — nuts, studs, standoffs, and captive panel screws — that are pressed permanently into sheet metal using a hardware insertion press. A precisely sized mounting hole is punched or laser-cut in the sheet, the fastener is positioned in the hole, and the press applies a controlled force that displaces the parent metal into the fastener's clinching groove. The result is a permanent, flush, vibration-resistant threaded attachment that cannot be removed without destroying the panel. PEM is the most widely used brand of self-clinching hardware; equivalent products are available under other brand names but PEM is the industry reference standard.

Tapping is unreliable in thin sheet metal (generally anything thinner than 3/16″) because the material doesn't provide enough depth for adequate thread engagement. Weld nuts work but add heat and distortion, require a weld operation, and can deposit spatter that needs cleanup. PEM hardware is a cold process — no heat, no chips, no distortion, no cleanup — that produces strong, flush, reusable threads in any sheet gauge, installed in seconds. It is the industry-standard solution for thin sheet metal threaded connections and is used in virtually every enclosure and panel product manufactured at commercial scale.

Lasertech installs PEM clinch nuts (Type S, SP, SS), clinch studs (Type FH, FHS), standoffs (Type SO, SOA), and captive panel screws (Type TRS, TFS, CPS) in inch and metric sizes across steel, stainless steel, and aluminum panels. If your drawing calls out a hardware type not listed here, contact us — we'll advise on availability and equivalent options.

Each PEM hardware type and thread size requires a specific mounting hole diameter — different from and larger than the thread size itself. For example, a ¼-20 Type S clinch nut requires a 0.281″ mounting hole, not a ¼″ hole. At Lasertech, mounting hole diameters are programmed directly into the flat pattern on the laser or punch machine — holes come out of the cutting operation already at the correct PEM diameter. No separate drilling step required. If you're supplying a drawing, include the PEM mounting hole diameter as the hole callout, or call out the PEM part number and we'll program the correct hole.

Generally, no. PEM hardware should be installed before powder coating, and threaded holes and standoff bores should be masked during coating to keep threads clear. Installing PEM hardware into a pre-coated panel can crack or chip the coating around the mounting hole and may compromise the clinch quality if coating buildup in the hole affects the mounting hole diameter. The standard sequence at Lasertech is: cut (with PEM holes to size) → form → insert hardware → weld → finish → mask threads → powder coat → remove masking → ship.

Call 770-461-9941 or use our online contact form. Provide your drawing with hardware callouts and mounting hole diameters (or PEM part numbers), panel material and gauge, and quantity. Fastener insertion can be quoted as part of a complete fabrication workflow — laser cut, form, insert hardware, weld, finish, powder coat, assemble — or as a standalone insertion-only operation on customer-supplied panels.

Strong Threads in Thin Metal —
In-House, In-Sequence

Request a Quote (770) 461-9941