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Sheet Metal
Engineering Calculators

Free tools for press brake operators, engineers, and fabricators. Calculate bend allowances, pressing forces, material weights, and more.

// Engineering Tools
01Bend Allowance 02Pressing Force 03Material Weight 04Laser Cut Time 05Sheet Utilization 06Min. Leg Length 07Bend Inner Radius 08Bend Layout 092D Bend Simulator 10DFM & Error Code Lookup 11Countersink Geometry 12Gauge → Thickness Chart 13Tap & Clearance Drill Chart 14Countersink Size Chart 15Hardware Size Chart 16Min / Max Part Sizes 17Deburring Size Limits 18Slot & Tab Size Chart
// 01 — Bend Allowance
Bend Allowance &
Flat Blank Length
FLAT BLANK LEG A LEG B BEND ZONE (BA)
Calculate the exact flat blank length needed before bending. Uses the K-Factor method for material stretch in the bend zone.
inches
inches
inches
degrees (inside)
inches ≈ thickness
// Formula

BA = (π/180) × angle × (r + K × t)  |  Flat = Leg A + Leg B + BA

// 02 — Pressing Force
Press Brake
Tonnage
Calculate the tonnage required for a bend. Verify your press brake has sufficient capacity. Add 20% safety margin to calculated tonnage.
ksi (UTS)
inches
inches
inches — typical 8× thickness
// Formula

Force = C × t² × UTS × L / V — result in tons. C = die factor, t = thickness, UTS in ksi, L = bend length, V = V-opening.

// 03 — Material Weight
Sheet &
Blank Weight
Calculate the weight of a flat sheet or blank. Useful for freight quoting, fixture loading, and safe handling requirements.
lb/in³
inches
inches
inches
number of sheets
// Formula

Weight = W × L × t × density (lbs)  |  ×0.4536 for kg

// 04 — Cut Time
Laser Cut
Time Estimator
Estimate cycle time based on cut path length, pierce count, and cutting speed. Does not include load/unload or rapid traverse time.
inches per minute (ipm)
linear inches
holes / slots / cutouts
seconds per pierce
number of parts
// Formula

Cycle = (Path ÷ Speed × 60) + (Pierces × Pierce Time)  |  Total = Cycle × Qty ÷ 60

// 05 — Sheet Utilization
Nesting
Efficiency
Estimate how efficiently parts nest on a standard sheet. Useful for cost planning and quoting before detailed nesting is run.
inches
inches
inches (bounding box)
inches (bounding box)
inches between parts
in² — actual geometry
// Formula

Cols = floor(W ÷ (PartW + gap))  |  Rows = floor(L ÷ (PartL + gap))  |  Util = Pcs × PartArea ÷ SheetArea × 100

// 06 — Min. Leg Length
Die Selection
& Min. Leg
Enter material thickness to find compatible dies. The minimum leg length is the shortest flange you can safely form without the part slipping off the die shoulders.
// Known Values

EV002 8mm V → 6.30 mm
EV004 12mm V → 9.30 mm
EV006 20mm V → 15.40 mm
EV/H W30/80° 30mm → 22.80 mm
EV W40/80° 40mm → 30.50 mm

mm
affects V-opening recommendation
Die Model Angle V-Opening Min. Leg Length Thickness Range Status
// 07 — Bend Inner Radius
Bend Inner
Radius
Estimate the inner bend radius achieved during air bending. The actual radius forms as a function of die V-opening and material. Harder materials spring back more and produce a larger effective radius.
// Air Bending Rule

Predicted IR ≈ V × mat. factor
Typical: V / 6 mild steel
Min. IR = t × material multiplier
Outer Radius = IR + thickness
Springback ≈ 3 × IR × σy / (E × t)

mm
mm
degrees (inside angle)
// 08 — Bend Layout
Flat Blank
Layout Calc
Enter outside finished dimensions — base width and flange heights — to get your flat blank length, bend deductions, and exactly where to draw your bend lines.
inches
degrees (inside)
inches ≈ t
// OUTSIDE FINISHED DIMENSIONS
inches (outside)
inches (outside)
inches (outside)
// Formula

BD = 2 × OSSB − BA  |  BA = (π/180) × angle × (r + K × t)  |  OSSB = tan(angle/2) × (r + t)
Flat = (Left − BD/2) + (Base − BD) + (Right − BD/2)

// FLAT BLANK DIAGRAM  — red dashed lines = bend lines