Bending and Drawing Industry Terminology

We switched to air bending to cut tonnage on the 6 mm part; Add 2 degrees overbend in air bending to compensate for springback; Use an 8x-thickness V-opening for stable air bends.

Measure r-values to quantify anisotropy before approving the coil; The flange cracked along the rolling direction due to anisotropy; Rotate the blank 90° to reduce anisotropy effects in the draw.

Program the X and R axes on the backgauge for the second bend; The backgauge fingers need a soft landing to avoid marking the part; Add a Z1/Z2 move to support the long blank during bending.

Update the BA in CAD so the flat length matches the formed part; BA increases with larger inside radii and angles; Use K-factor 0.38 to estimate BA for this steel.

Our press brake uses BD tables, not BA, for nesting; Increase BD by 0.5 mm after switching to a tighter die; The ERP’s flat pattern is off because the BD library is outdated.

Specify an inside radius of 1.5t to avoid cracking; A larger radius reduced tonnage and springback scatter; The print’s sharp corner is unrealistic—call out a 2 mm inside radius.

Add bend relief near the slot to stop edge cracking; Laser a rectangular relief 1.5t deep before forming; The cosmetic distortion disappeared after we added bend reliefs.

Increase BHF in 5% steps to remove draw wrinkles; The new lube lets us reduce BHF by 10%; We mapped BHF vs. cracking in tryout to find the process window.

Set clearance to 8% per side for low-carbon steel; Excessive burrs indicate our clearance is too large; Tighter clearance improved hole roundness but increased tonnage.

We coined the 0.5 mm part for ±0.25° angle accuracy; Coining eliminated springback scatter on the bracket; Tool life dropped after switching to coining—plan regrinds.

We require Cpk ≥ 1.33 on bend angle; Capability improved to Cp 2.0 after adding a radius gauge; Low Cpk on flange length triggered a corrective action.

The first draw forms the cup; the second redraw sets the height; We hit the limiting draw ratio at 2.1; Add draw beads to control flange flow.

Increase die radius from 4t to 6t to ease flow; A sharp die radius caused galling and splits; The tooling change to a larger radius improved the FLD margin.

Move the draw bead 10 mm to balance left-right flow; A higher bead height stopped flange waves; We used adjustable beads in tryout to define the final binder.

Our LDR is 2.0 for this grade; Reduce the first draw ratio and add a redraw; The simulation shows the draw ratio is too aggressive at the corners.

The new HSLA has lower ductility—expect more splits; Ductility drops after strain aging, so store coils properly; Choose a grade with higher ductility for the complex emboss.

The 20% elongation spec is borderline for this draw; Uniform elongation is more relevant for the stretch areas; Heat lot 7 had lower elongation, causing edge cracks.

The hole split during stretch flanging—add a larger radius; Shrink flanging caused wrinkles we had to restrike; We adjusted lube for the perimeter flange to improve quality.

The new coating reduced formability due to friction; We used an FLD to quantify formability margin; Formability limits drove the design change to a shallower draw.

The strain map sits 5% below the FLD curve—safe; Hot spots above the FLD explain the corner splits; We updated the FLD for the new grade and lube.

Mark grain direction on blanks for consistent bending; Bend perpendicular to grain to reduce edge cracking; Earing aligned with grain confirms anisotropy.

Add a 0.8 mm pre-hem radius to avoid splits; Automotive door hems require tight cosmetic control; The hem die needs shims to fix the closed angle.

The can body is formed with three ironing stages; Excessive ironing caused galling on the ring; We increased lube viscosity to stabilize the ironing load.

Blanks arrive JIT to feed the press cells; A JIT disruption shut the draw line after two hours; We leveled demand to make JIT feasible for the brake area.

Use K=0.42 for this aluminum grade; The CAM post uses K-factor by default for flats; Calibrate K-factor with a bend test coupon.

The grade’s average r=1.8 supports the draw depth; Low r in TD explains the corner splits; We specified r̄ ≥ 1.6 for sourcing.

Switch to a heavier lube for the second draw; Inadequate lubrication increased BHF requirements; The coating is lube-sensitive—trial two chemistries.

Add a 4-ball mandrel for the tight 1.5D bend; Mandrel position is 1–2 mm ahead of the tangent; Wear on the mandrel tip caused tube scoring.

Our angle gauge failed GR&R at 28%—not acceptable; Perform MSA before launching SPC on flange length; New vision system passed bias and linearity tests.

Necking begins near the punch corner on the map; Reducing draw ratio delayed necking onset; The restrike eliminated the necked zone.

The neutral axis shifts with material and die opening; Our flat pattern error came from a wrong neutral axis assumption; Use bend tests to locate the neutral axis empirically.

The n-value of 0.22 supports the emboss; Low n in this lot caused sensitivity to splits; We target n ≥ 0.18 for this family of parts.

The draw press OEE improved to 78% after TPM; Micro-stops and quality losses are dragging OEE; Post changeover SMED boosted performance and OEE.

We held ovality to 6% with a tighter mandrel; Excess ovality is causing assembly leaks; Specify max 8% ovality for supplier acceptance.

Program a 92° hit to net 90° after springback; Overbending by 3° stabilized the angle capability; We reduced overbend after switching to coining.

A sensor poka‑yoke blocks the press if the blank is misoriented; The die includes a form-then-cut sequence to prevent double hits; We added angle verification as a poka‑yoke before packout.

PPAP requires material certs and capability on bend angle; We submitted a Level 3 PPAP with dimensional layout and MSA; Tooling changes triggered a PPAP resubmission.

The 170‑ton press brake handles 3 m parts; We added an R-axis to the brake for box forms; The brake’s crowning compensates for bed deflection.

Increase punch radius to reduce corner splits; The punch coating cut galling and cleanup; Punch wear shifted the angle by 0.7°.

RCA showed insufficient lube caused the cracking; We used a fishbone to sort draw failure factors; The team’s 5 Whys led to a BHF control plan.

Start SPC on bend angle using an X‑bar/R chart; SPC signaled a shift after the tool regrind; We tightened lube control to bring SPC back in limits.

Expect 1–3° springback on this grade at R/t=1; Coining minimized springback variation; We used overbending and a smaller V-die to counter springback.

The brake cell must hit a 45‑sec takt time; We rebalanced stations to meet takt after adding deburr; OEE losses made us miss takt in the draw area.

TPM cut unplanned downtime on the press by 40%; We added daily lubrication checks to the TPM board; TPM pillars drove our OEE gains.

Tryout showed we needed +10% BHF; We blue’d the die to correct contact in the corner; Adjustable beads accelerated the tryout curve.

VSM revealed WIP buildup between draw and trim; The future-state VSM adds a supermarket before the brake; We cut lead time 30% based on the VSM plan.

Cap WIP to two racks between draw and pierce; Daily WIP walks highlight flow issues; WIP dropped after SMED on the brake.

Our CAD uses Y-factor tables by material; Update Y-factor after the bend test coupons; Using the wrong Y-factor shifted all flat lengths.

The DP600’s higher yield demands a larger die opening; We adjusted overbend for the new coil’s yield strength; Yield variation explains the angle drift in SPC.

Switch to a zinc-friendly lube for GA-coated parts; Galvanized flakes caused die galling—clean more often; The GI coating changed the draw-in and BHF needs.