Stamping Industry Terminology

Advanced High-Strength Steel (AHSS)

A family of steels (e.g., DP, TRIP, CP, MS) engineered for high strength-to-weight ratios; harder to form and trim, prone to edge cracking and springback, often requiring specialized tooling, coatings, and process controls.

Use extra punch-to-die clearance on DP980 to reduce edge fracture; Switch to PVD-coated punches to combat galling on TRIP steels; Apply overbend and add drawbeads to tame AHSS springback.

Amortization (Tooling)

Allocating the capital cost of tooling over an agreed production volume/time, typically recovered through piece price or separate tooling charge.

Amortize the new progressive die over 500,000 parts; Add $0.12/tooling amortization to the quoted piece price; End amortization early if EAU falls below forecast.

APQP (Advanced Product Quality Planning)

A structured, cross-functional planning process (common in automotive) for launching products, integrating risk analysis, process design, validation, and customer approvals.

Kick off APQP with the cross-functional team and timing chart; Use APQP deliverables to support PPAP; Update APQP when the strip layout changes.

Bend Allowance

The arc length of the neutral axis in a bend used to calculate flat pattern length; depends on thickness, bend radius, angle, and K-factor.

Add bend allowance to each flange when developing the blank; Use K=0.33 for initial bend allowance estimate on mild steel; Adjust bend allowance after first-article measurement shows short flanges.

Blank

A precut flat piece of sheet/coil stock that will be formed into a part; produced by blanking, shearing, laser cutting, or coil-fed dies.

Laser blank the pilot holes for transfer forming; Switch to coil-fed strip instead of separate blanks; Optimize blank shape to improve material yield.

Blank Utilization

The percentage of material that becomes the part (vs. scrap/skeleton) in a stamping process; a key cost driver.

Improve blank utilization from 72% to 80% by redesigning the carrier; Run a nesting study to cut coil scrap; Quote assumes 78% utilization at current strip layout.

Blanking

A shearing process that cuts flat shapes from sheet/coil; the slug is the part (blanking) or the hole (piercing).

Increase die clearance to reduce blanking burr height; Monitor tonnage spikes during blanking stations; Fineblanking alternative considered for cosmetic edge.

Bolster Plate

The thick, machined plate on the press bed that supports the lower die and provides T-slots for clamping.

Verify bolster flatness before tryout; Use standardized T-slot clamps on the bolster; Install a rolling bolster to speed QDC.

Burr

A raised edge or small ridge of material left after shearing or trimming; controlled by die clearance, sharpness, and material.

Deburr parts to meet ≤0.05 mm burr spec; Sharpen the punch to lower burr height; Increase clearance to reduce work hardening and burrs.

Coil Straightener

Machine with adjustable rolls that removes coil set, crossbow, and minor camber before feeding strip into the press.

Add more straightener wrap to flatten AHSS; Adjust straightener rolls to fix panel oil-canning; Verify straightener capacity for 6 mm HSLA.

Control Plan

Document defining critical characteristics, measurement methods, sampling frequencies, and reaction plans to control the stamping process.

Add burr height to the control plan as a critical-to-quality check; Update reaction plan for misfeed alarms; Align control plan with PFMEA severity rankings.

Cp/Cpk

Process capability indices; Cp measures potential capability (spread vs. spec), Cpk accounts for centering relative to spec limits.

Target Cpk ≥1.33 on hole position; Investigate tool wear after Cpk on flange length drops; Improve centering to raise Cpk while Cp stays constant.

Deep Drawing

Forming process that pulls a blank into a die cavity to create cups or shells; risks include wrinkling, tearing, and earing.

Add drawbeads to prevent flange wrinkling; Check draw ratio before committing to one-hit draw; Use a cushion to control blankholder force during deep draw.

Die Crash

Unintended collision or interference within the die or between die and press, often due to misfeed, sensor failure, or setup error; can cause severe damage and downtime.

Die crashed after a short feed bypassed protection; Add slug-detect sensors to avoid repeat crashes; Conduct 8D after crash to prevent recurrence.

Die Maintenance

Preventive and corrective activities to keep tooling in spec: sharpening, replacing wear components, lubrication, re-spotting, and timing adjustments.

Schedule PM after 50,000 hits for sharpening; Replace worn guide bushings causing station misalignment; Track maintenance hours by die to refine costing.

Die Protection

Sensors and logic that monitor strip and part conditions to stop the press before damage (e.g., short feed, part-out, slug detect, over-tonnage).

Add photoeye for part-out detection; Set misfeed window in the die protection controller; Tie tonnage alarm into the press stop circuit.

Die Set

Assembly of upper and lower plates guided by posts and bushings that houses punches, dies, strippers, and cams.

Order a heavy-duty die set for AHSS; Replace worn guide posts to improve station accuracy; Verify die set shut height fits the press.

Drawbead

A bead formed in the die or binder to restrict and control material flow during drawing, balancing wrinkling vs. tearing.

Tighten drawbead in the corner to reduce splits; Use adjustable drawbeads during tryout; Simulate drawbead restraining force in FEA.

EAU (Estimated Annual Usage)

Forecasted number of parts the customer expects to purchase annually; used for capacity planning, tooling amortization, and inventory strategy.

Quote based on EAU of 300k pieces; Recalculate amortization when EAU is revised; Validate press capacity against peak EAU demand.

Fineblanking

Precision shearing process using triple-action presses, small die clearances, and a V-ring to produce near-berless edges and tight tolerances.

Switch to fineblanking for gear tooth quality; Compare fineblanking cost vs. blanking plus machining; Specify fineblanked edge for improved fatigue life.

FMEA (Failure Modes and Effects Analysis)

Structured method (DFMEA/PFMEA) to identify potential failures, their effects, and risk priority, leading to mitigation actions.

Add misfeed as a PFMEA failure mode; Reduce RPN by adding die protection; Update PFMEA after process change to lubricant.

Gage R&R

Measurement System Analysis evaluating repeatability and reproducibility to ensure measurement variation is small vs. part variation.

Conduct Gage R&R on burr height measurement; Replace worn caliper jaws after low repeatability; Train operators to improve reproducibility on hole position checks.

Galling

Adhesive wear and material transfer on tooling surfaces due to friction/pressure, common with stainless and AHSS.

Apply TiCN coating to reduce galling; Increase lubricant viscosity for the draw; Polish die radii to lower contact friction.

GD&T (Geometric Dimensioning and Tolerancing)

Symbolic system to define allowable part geometry variation relative to datums (e.g., position, flatness, perpendicularity).

Use true position for hole location on bracket; Set datum scheme A-B-C for body side panel; Check flatness on the drawn pan per GD&T callout.

Hemming

Folding a flange over onto itself (often 180°) for edge finish, stiffness, or joining, commonly in closures.

Add pre-hem station to reduce splits; Tighten hem roller gap to hit thickness spec; Inspect hem quality for cosmetic panels.

Hot Stamping (Press Hardening)

Forming and quenching boron steel (e.g., 22MnB5) in a heated state to achieve very high strength in the final part.

Convert B-pillar to hot stamp for crash performance; Validate die cooling for martensitic structure; Use aluminized blanks to prevent scale during heating.

In-Die Sensing

Integration of sensors (e.g., piezo, proximity, optical) in the die to detect strip, slugs, part-out, and force signatures in real time.

Add slug-detect sensor under the pierce station; Wire short-feed sensor into the press control; Trend sensor data for predictive maintenance.

JIT (Just-In-Time)

Production and logistics strategy to deliver the right quantity at the right time with minimal inventory and waste.

Ship stamped parts JIT to the assembly line; Level-load the press schedule to support JIT; Use heijunka boxes to smooth JIT flow.

Kanban

A visual pull system that signals replenishment based on consumption, controlling WIP and finished goods.

Implement two-bin kanban for coil sleeves; Size kanban cards for 1.5 days of demand; Trigger die sharpening via kanban when hits reach limit.

Lean Manufacturing

Systematic elimination of waste (muda) through flow, pull, standardized work, and continual improvement.

Map press setup with a value stream map; Kaizen to reduce coil changeover waste; Standardize work for die clamp sequence.

Mechanical Press

Press with flywheel, clutch/brake, and crank/knuckle linkage; provides high speed with a defined tonnage curve peaking near BDC.

Choose a 400-ton mechanical press for blanking; Check tonnage at forming height vs. BDC; Increase SPM on shallow draw with mechanical press.

Misfeed

Incorrect advancement of the strip (short, long, or skew) causing timing errors and risk of crash; detected by pilots or sensors.

Stop the press on short-feed alarm; Investigate feeder roll slippage causing misfeeds; Add pilot release timing to prevent skew feeds.

Nitrogen Gas Spring

Self-contained gas cylinders providing consistent force for strippers, pressure pads, and cams in dies.

Set gas springs to 1,500 psi for binder force; Replace leaking nitrogen cylinders during PM; Verify total spring force vs. press cushion capacity.

OEE (Overall Equipment Effectiveness)

Composite metric of manufacturing productivity: Availability × Performance × Quality; highlights losses from downtime, speed, and defects.

Raise OEE by cutting changeover time; Track OEE by part family on Press #12; Quality loss from burrs reduced OEE by 3%.

Pilot Hole

A precisely located hole in the strip used by pilots to register and lock the strip to the die timing.

Add 6 mm pilot holes every pitch; Check pilot timing during first hit; Ream pilot pins after wear causes registration error.

PPAP (Production Part Approval Process)

Customer approval package confirming the supplier can meet requirements consistently, including PSW, capability, material certs, and control plans.

Submit Level 3 PPAP with 300-piece run; Include gage R&R and capability studies in PPAP; Hold shipment until PPAP is approved.

Progressive Die

A coil-fed die with multiple stations performing operations (pierce, form, trim) progressively each press stroke, producing a finished part each hit.

Design 12-station progressive for the bracket; Optimize pitch to balance utilization and SPM; Add a carry web to support small parts.

QDC (Quick Die Change)

Methods and equipment that reduce changeover time (e.g., hydraulic clamps, rolling bolsters, die carts, standardized setups).

Install hydraulic die clamps for QDC; Use pre-staged die sets to cut changeover in half; Combine QDC with SMED to improve press uptime.

Ram/Slide

The moving member of the press that drives the upper die; stroke length and slide adjustment define shut height and forming window.

Adjust slide down 2 mm to hit shut height; Verify slide parallelism before tryout; Monitor slide position for servo profiles.

Run at Rate

A production trial demonstrating the process can meet volume, quality, and timing requirements under normal conditions.

Complete an 8-hour run at rate before PPAP; Use customer tool for run-at-rate validation; Record OEE and scrap during the run.

Servo Press

Press driven by a servo motor allowing programmable slide motion, variable speed, dwell at bottom, and optimized forming energy.

Program a dwell at BDC to reduce springback; Slow approach speed to cut noise and burrs; Use servo profile to form AHSS without splitting.

Shut Height

Distance from press bed/bolster to the slide face at bottom dead center, with slide adjustment considered; die must fit this window.

Confirm die fits the 500 mm shut height; Adjust shut height for new die set thickness; Include risers to meet press shut height.

SMED (Single-Minute Exchange of Die)

Methodology to reduce changeover time by converting internal steps to external, streamlining clamping, and standardizing setups.

Pre-stage coils to externalize setup; Use quick-connects for lube lines per SMED; Time each setup step for kaizen.

SPC (Statistical Process Control)

Using control charts and statistics to monitor process stability and detect special causes before defects occur.

Plot X̄-R charts on flange length; Trigger investigation on out-of-control signal; Reduce sampling once process shows control.

Springback

Elastic recovery after forming that causes dimensional deviations; influenced by material strength, thickness, and tooling geometry.

Add overbend to compensate for springback; Use restrike station to correct angles; Increase binder force to control panel springback.

Strip Layout

Engineering of the progressive strip: station sequence, pitch, carriers, pilots, scrap management, and material yield.

Redesign strip layout to add an extra form station; Increase pitch to clear the cam; Add scrap chutes to prevent slug piling.

Takt Time

The pace of production required to meet customer demand (available time divided by demand).

Balance the press line to takt time; Add a parallel press to meet takt; Adjust staffing to match takt during peak.

Tonnage Monitor

Instrumentation that measures press load per stroke; used for die protection, process control, and overload prevention.

Set high/low tonnage limits for each station; Investigate rising tonnage indicating tool wear; Stop press on over-tonnage alarm.

Transfer Stamping

Process where a blank is moved between multiple dies/stations by transfer fingers or tri-axis transfer, enabling complex forms.

Add transfer fingers to handle large panels; Time the transfer to avoid part collision; Use draw in station 1, trim in station 2, pierce in station 3.

Tryout

The iterative process of proving out and tuning new or modified dies to achieve dimension, surface, and process capability targets.

Blue-in and spot to improve contact; Adjust drawbeads during tryout to eliminate splits; Document changes before moving to production.