Cut clean, load-bearing threads directly into steel, stainless, and aluminum — in-house, in-sequence, and on the same floor as the laser, press brake, and welder. Inch and metric, coarse and fine, from small clearance holes to structural fastening points in thick plate.
Tapping is the process of cutting helical thread profiles into a pre-drilled hole, creating a female threaded connection — the receiving end of a bolt or screw. The tap is a hardened cutting tool with matching thread geometry that removes metal as it advances into the hole, leaving a precisely formed internal thread.
It's one of the most common secondary operations in fabricated metalwork — and one of the most important to get right. A stripped or under-engaged thread causes fastener failure in service. At Lasertech, tapping is performed in-house, in-sequence with fabrication, with the correct tap geometry and lubricant for each material.
A precisely sized tap drill — smaller than the finished thread diameter — creates the pilot hole. Tap drill size is calculated to leave the correct percentage of thread engagement without overtaxing the tap or stripping the thread during use. Wrong tap drill size is the most common cause of tap breakage and poor thread quality.
A countersink or chamfer tool creates a small lead-in at the hole entrance. The chamfer guides the tap into alignment, prevents a raised burr at the thread entry, and produces a cleaner thread start — particularly important on cosmetic surfaces and parts that will be powder coated.
The tap is driven into the hole using a CNC tapping head, tapping arm, or hand tap wrench — with cutting fluid applied to lubricate the cutting action, flush chips, and reduce heat. The tap is advanced in controlled increments and periodically reversed to break and clear chips, preventing chip packing and tap breakage.
Tapped holes are gauged with a thread plug gauge or verified with a fastener of the specified class to confirm full engagement, correct pitch, and proper thread class. Tapped holes flagged for powder coating masking are recorded and communicated to the coating team to ensure threads aren't filled with powder.
Tapping after fabrication — and before coating — requires coordination between operations. In-house tapping eliminates the scheduling, transit, and communication gaps that occur when a separate machine shop handles threading on parts sourced from a different fabricator.
Tapping in-house means we control when threading happens relative to forming, welding, and finishing — before or after powder coating as the drawing requires, without coordinating with a separate vendor's schedule.
No shipment to a machine shop and back. Threading completes as part of the standard fabrication flow — same facility, same timeline, no added lead time for a secondary vendor queue.
Tapped holes that must remain clear of powder coat are identified and communicated directly to the coating team. No risk of threads being filled when tapping and coating happen under the same roof with the same quality oversight.
If a thread is wrong, you call one shop. No finger-pointing between a fabricator who "just drilled the hole" and a tapping shop that "just ran the tap." One team, one invoice, one point of contact.
Lasertech's tapping services span CNC-driven production tapping, manual hand tapping, and thread forming — covering the full range of threading requirements encountered in sheet metal and light structural fabrication.
Spindle-synchronized tapping performed on CNC machining centers with rigid tap holders and programmed feed rates matched to thread pitch. CNC tapping delivers consistent hole-to-hole thread quality across production runs — same depth, same form, same position every time. Eliminates the variability of hand tapping on high-volume jobs and is the standard method for production quantities of threaded holes in steel, stainless, and aluminum.
Production Quantities · Consistent QualityManual tapping performed with a tap wrench and hand-held tap — used for prototype and low-volume work, awkward or deep features inaccessible to a machine spindle, final assembly tapping on assembled structures, and threads in locations requiring tactile feedback to avoid tap breakage. Skilled operators use the appropriate tap geometry (taper, plug, or bottoming tap) and apply cutting fluid suited to the material.
Prototype · Low Volume · Restricted AccessCold-forming of threads by displacing rather than cutting material — a thread-forming tap rolls the thread profile into the metal without producing chips. Forming produces stronger threads (work-hardened root material), eliminates chip-clearing requirements, and is ideal for ductile materials such as aluminum and mild steel in blind hole applications. Not appropriate for brittle materials or cast components.
Chipless · Stronger Thread · Blind HolesStandard Unified National Coarse (UNC) and Unified National Fine (UNF) threads covering the full range of sizes used in sheet metal fabrication and light structural work — from #4-40 through 1/2-13 and corresponding fine pitch series. Coarse pitch is the default for most structural and assembly applications; fine pitch is specified where vibration resistance or adjustment precision is required.
#4-40 through ½-13 · UNC & UNFISO metric coarse and fine threads in the standard M-series used in international OEM manufacturing, electronics, enclosures, and any application where metric fasteners are specified. Common sizes from M3 through M12 are routinely stocked and tapped; less common sizes and thread classes available on request. Metric callouts should specify pitch (e.g., M6×1.0) if fine series is required.
M3–M12 · Coarse & Fine PitchTapped holes that must remain clear of powder coating are identified, masked with threaded plastic plugs or tape prior to coating, and inspected after the coating process to ensure threads are clean and fully functional. Masking is coordinated directly between the tapping and coating operations — no separate instruction set required from the customer. Call out masking requirements on the drawing or in your quote notes.
Plastic Plugs · Pre-Coat · Post-Coat VerifyThe sizes below represent the most frequently tapped threads in sheet metal and structural fabrication. Sizes not listed are available on request — contact us with your callout and material.
Thread strength depends on engagement length — the number of threads in contact between the fastener and the tapped hole. The general rule is a minimum of 4 full threads of engagement for a reliable structural joint. Fewer than 3 threads is generally considered unreliable under load.
For sheet metal gauges thinner than about 3/16″, tapping produces insufficient engagement and PEM self-clinching hardware should be considered instead. For plate, structural sections, and thicker bar stock, tapping is highly effective and cost-efficient.
If your drawing shows a thread callout on thin sheet metal, our team will flag it and recommend whether to proceed with tapping or switch to PEM hardware — before we quote, not after we've already drilled the holes. Call 770-461-9941 or include a note in your quote request.
Both tapping and PEM self-clinching fasteners add threaded connection points to sheet metal — but they solve different problems. The right choice depends on material thickness, load requirements, accessibility, and volume. Lasertech offers both in-house.
Use this guide to determine the right threading approach. When in doubt, share your drawing with our team — we'll recommend the right method before quoting.
Thick plate, structural angles, bar stock, and heavy brackets all provide sufficient engagement for tapped threads. Tapping is cost-effective and produces no additional hardware cost.
High axial clamp loads in thick material are well-suited to tapped threads — the full thread depth engages the fastener along its entire shank.
Weldments, CNC-machined features, and structural steel sections are all good candidates for tapping — material is typically thick enough and hardness suits standard taps.
Standard sheet gauges don't provide enough material for reliable tapped threads. PEM hardware was designed specifically for this application.
PEM studs and clinch nuts sit flush with the panel surface — ideal for enclosures, panels, and assemblies where clearance or aesthetics prohibit protruding hardware.
PEM hardware maintains thread integrity through many assembly cycles — tapped threads in thin material strip quickly under repeated use.
Each material responds differently to tapping — tap geometry, cutting speed, and lubricant must be matched to the material to produce quality threads and avoid tap breakage. Lasertech's team selects the right approach for each job.
The most common tapped material. Good machinability. Standard high-speed steel (HSS) spiral-point taps with a sulfur-based cutting oil produce clean, consistent threads across a wide range of gauges and pitch sizes. Coarse threads preferred for most structural applications.
HSS Tap · Sulfurized Oil · Coarse PreferredWork-hardens rapidly during cutting — requires sharp taps, consistent feed rate, and appropriate lubricant to prevent galling and tap seizure. Spiral-flute taps with a synthetic cutting fluid are used. Slower speeds than mild steel. More frequent tap replacement required.
Spiral Flute · Synthetic Fluid · Careful Speed ControlSoft and ductile — cuts easily but prone to chip loading and thread tearing if feed rate is wrong or chip clearance is inadequate. Spiral-flute or thread-forming taps with a petroleum-based cutting fluid work well. Thread forming is particularly effective in aluminum — no chips, stronger root material.
Thread Forming Preferred · Petroleum FluidZinc coating on galvanized material can load tap flutes and interfere with chip clearance. Through-hole tapping is preferred to allow chips to exit. Zinc removed from thread area is addressed in finishing before powder coating to restore corrosion protection.
Through-Hole Preferred · Zinc-Rich Primer NotedA complete thread callout on a drawing eliminates ambiguity and ensures the correct thread is produced on the first run. The standard callout format conveys size, pitch, thread class, depth, and direction — all in a single leader note.
If tapped holes must remain clear of powder coat, add a note to the drawing: "MASK TAPPED HOLES BEFORE POWDER COAT" or call out individual holes with a leader note. Our team coordinates masking directly between tapping and coating operations.
Tapping sequence relative to other operations depends on the part — tapping before welding risks filling threads with spatter; tapping after powder coat risks thread damage during masking removal. Lasertech sequences tapping correctly for each job.
Tap drill holes punched or laser-cut to size from program.
Press brake forming and welding — tapping held until after welding to protect threads from spatter.
CNC or hand tapping after welding, before finishing and powder coat.
Threads masked. Part deburred, blasted, powder coated. Plugs removed after cure.
Hardware installed, kitted, and shipped ready to use.
Tapped threads appear in virtually every sector of fabricated metalwork where bolted connections are required and material thickness is adequate for reliable engagement.
Access panel fastening, conduit mounting brackets, structural frame connections — typically in ¼″ to ½″ plate where tapping delivers excellent engagement.
Back panel mounting threads, ground lug attachment points, and DIN rail fastening in thicker gauge steel — tapped before powder coat with threads masked during coating.
Machine frames, guards, and structural weldments requiring load-bearing bolted connections in thick steel — where tap engagement depth is not a limiting factor.
Stainless steel structural sections and mounting brackets — tapped with appropriate tooling and lubricant for 304/316 stainless to avoid galling and produce clean threads.
Aluminum and steel structural brackets, mounting tabs, and chassis components — thread forming preferred in aluminum for stronger root material without chip generation.
Mounting and attachment points in decorative metal assemblies — tapped in plate sections where access for through-bolting is limited and flush fastening is required.
Unit mounting brackets, pipe support weldments, and equipment support frames in carbon steel plate — high-volume tapping sequences programmed into the CNC workflow.
Target frames, steel structural components, and mounting hardware for range installations — tapped in thick structural steel for durable, field-serviceable bolted connections.
Common questions about tapping services at Lasertech Metal Works.
Lasertech provides CNC tapping, hand tapping, and thread forming in-house. We tap UNC and UNF inch threads and ISO metric coarse and fine threads in steel, stainless steel, and aluminum — from #4-40 through 1/2-13 and M3 through M12 and beyond. Tapping is performed as part of the fabrication sequence, with thread masking coordinated directly with the powder coating team for holes that must remain thread-clear after coating.
Tapping is the right choice when material is thick enough to provide at least 4 full threads of engagement — generally ¼″ plate or thicker for ¼-20 threads. For thin sheet metal (16 gauge through 3/16″), standard tapping produces too few threads for reliable structural hold, and PEM self-clinching hardware is the better solution. PEM hardware is also better when you need flush panel-mounted threads or threads that will be assembled and disassembled frequently. Lasertech offers both in-house — and our team will flag material thickness concerns before quoting if a tapping callout appears on thin material.
Tapped holes that must remain clear of powder coat are masked with threaded plastic plugs sized to the specific thread before the part enters the coating process. Plugs are installed after tapping, before pretreatment, and removed after the coating has cured. The tapping team communicates masked holes directly to the coating team — no separate instruction from the customer is needed as long as masking is called out on the drawing or in the quote request.
Thread forming (also called cold forming) displaces rather than cuts material — the tap rolls the thread profile into the metal without removing chips. The result is a stronger thread (the material at the thread root is work-hardened by the forming action), no chip generation, and better suitability for blind holes where chip evacuation is difficult. Thread forming is most effective in ductile materials like aluminum and mild steel. It is not appropriate for brittle materials. In aluminum especially, formed threads are significantly stronger than cut threads and are Lasertech's preferred method where the geometry permits.
A complete thread callout includes: nominal size, threads per inch (inch) or pitch in mm (metric), thread series (UNC, UNF, or metric), thread class (2B is standard for most applications), and depth (THRU or a specific depth dimension). Example: ¼-20 UNC-2B THRU or M6×1.0-6H 12 DP. If masking is required, add a note: "MASK TAPPED HOLES BEFORE POWDER COAT." If you're unsure about callout format, submit the drawing and we'll review it — call 770-461-9941 or use our contact form.
Call 770-461-9941 or use our online contact form. Provide your drawing with thread callouts, material specification, quantity, and any masking or special tolerance requirements. Tapping can be quoted as part of a complete fabrication-to-coating workflow or as a standalone operation on supplied parts.