Press Brake Machines USA

Every figure in this chart is calculated from the standard air-bend formula rather than copied from another chart, and the arithmetic for each row is shown underneath so you can audit it against your own numbers.

Scroll table →

Show your work — every row, calculated.
Formula: T = (650 × t²) ÷ V, where T is US tons per lineal foot, t is thickness in inches, V is V-die opening in inches. With V = 8t the expression reduces to T = 650t ÷ 8 = 81.25 × t, which is a useful sanity check on every row below.
• 16 GA, t = 0.060: V = 8 × 0.060 = 0.48. t² = 0.003600. 650 × 0.003600 = 2.340. 2.340 ÷ 0.48 = 4.875 → 4.9. Check: 81.25 × 0.060 = 4.875 ✓
• 14 GA, t = 0.075: V = 0.60. t² = 0.005625. 650 × 0.005625 = 3.656. 3.656 ÷ 0.60 = 6.094 → 6.1. Check: 81.25 × 0.075 = 6.094 ✓
• 11 GA, t = 0.120: V = 0.96. t² = 0.014400. 650 × 0.014400 = 9.360. 9.360 ÷ 0.96 = 9.750 → 9.8. Check: 81.25 × 0.120 = 9.750 ✓
• 3/16 in, t = 0.1875: V = 1.50. t² = 0.035156. 650 × 0.035156 = 22.852. 22.852 ÷ 1.50 = 15.234 → 15.2. Check: 81.25 × 0.1875 = 15.234 ✓
• 1/4 in, t = 0.250: V = 2.00. t² = 0.062500. 650 × 0.062500 = 40.625. 40.625 ÷ 2.00 = 20.313 → 20.3. Check: 81.25 × 0.250 = 20.313 ✓
• 3/8 in, t = 0.375: V = 3.00. t² = 0.140625. 650 × 0.140625 = 91.406. 91.406 ÷ 3.00 = 30.469 → 30.5. Check: 81.25 × 0.375 = 30.469 ✓
• 1/2 in, t = 0.500: V = 4.00. t² = 0.250000. 650 × 0.250000 = 162.500. 162.500 ÷ 4.00 = 40.625 → 40.6. Check: 81.25 × 0.500 = 40.625 ✓
Multipliers: stainless column = mild steel × 1.5; aluminum column = mild steel × 0.5; margin column = mild steel × 1.2. Published multipliers, ADH Machine Tool.
Scaling to your part: these are tons per foot. A 1/4 in mild steel part with a 6 ft bend needs 20.3 × 6 = 122 tons, or 146 tons with the 20% margin. Then check that figure against the limits in Table 6 before you buy anything.
What this does not cover: the 650 constant assumes air bending 60,000 PSI mild steel. Bottoming runs roughly 4–5× the air-bend figure and coining roughly 10×. Higher-strength steels raise the constant. Change any of those and this chart does not apply.

Sources for formula and multipliers: ADH Machine Tool, What Is Press Brake Tonnage · RMFG, Press Brake Tonnage Chart & Calculator. The tonnage values in the table are UmproTech's own calculation from that published formula, shown in full above so they can be audited.

Every tonnage chart online tells you how much force a bend needs; this one tells you how much force your machine and tooling can legally take in one spot, which is the number that actually bows beds and cracks tooling.

Scroll table →

Show your work — the 60% span rule, every row.
Rule: safe tons per foot = rated tons ÷ (0.60 × span in feet), and the shortest bend that may be run at full rated tonnage is 0.60 × span. Below that length, tonnage must be reduced.
• 60 t, 6 ft span: 0.60 × 6 = 3.6. 60 ÷ 3.6 = 16.67 tons/ft. Shortest full-tonnage bend = 3.6 ft = 43.2 in. Load check: 60 ÷ 43.2 = 1.39 tons/in.
• 100 t, 8 ft span: 0.60 × 8 = 4.8. 100 ÷ 4.8 = 20.83 tons/ft. Shortest full-tonnage bend = 4.8 ft = 57.6 in. Load check: 100 ÷ 57.6 = 1.74 tons/in.
• 150 t, 10 ft span: 0.60 × 10 = 6.0. 150 ÷ 6.0 = 25.00 tons/ft. Shortest full-tonnage bend = 6.0 ft = 72 in. Load check: 150 ÷ 72 = 2.08 tons/in.
• 200 t, 12 ft span: 0.60 × 12 = 7.2. 200 ÷ 7.2 = 27.78 tons/ft. Shortest full-tonnage bend = 7.2 ft = 86.4 in. Load check: 200 ÷ 86.4 = 2.31 tons/in.
• 300 t, 14 ft span: 0.60 × 14 = 8.4. 300 ÷ 8.4 = 35.71 tons/ft. Shortest full-tonnage bend = 8.4 ft = 100.8 in. Load check: 300 ÷ 100.8 = 2.98 tons/in.
How to read the "load at that bend" column: it is the tons-per-inch the tooling sees if you apply the machine's full rated tonnage across the shortest permitted bend. Compare it to the tooling's concentrated-load rating in Table 6b. On every row above it lands well under even a 4 tons/in tooling rating — which is the point: the span rule, followed correctly, keeps you inside the tooling limit. Break the span rule with a short bend at full tonnage and both limits go at once.
Why derate: published guidance is to work at 70–80% of rated capacity rather than at the nameplate, which is what the last column shows. A 100-ton machine is a 70–80 ton working machine.

Product-page rule: replace the illustrative span classes above with the exact model's rated tonnage, bed length and clear housing-to-housing span. Do not present the round classes as UmproTech machine specifications.

Sources: ADH Machine Tool, Press Brake Bending Capacity: Calculate Safe Tons Per Foot Before A Short Bend (60% span rule) · Jeelix, Press Brake Tooling Hardness (tooling concentrated-load rating and derate guidance). Tons-per-foot, shortest-bend and tons-per-inch values are UmproTech's calculation from that published rule, shown in full above.

The second limit is the tooling itself: standard press brake tooling profiles carry a published concentrated-load rating of 4 to 12 tons per inch, and guidance is to work at 70–80% of it.

Scroll table →

Show your work. Derated rating = rating × 0.80 and rating × 0.70. Max load over a 12 in bend = rating × 12. Worked: 4 × 0.80 = 3.2 and 4 × 0.70 = 2.8; 4 × 12 = 48 t, 48 × 0.80 = 38.4 t, 48 × 0.70 = 33.6 t. Same pattern at 6, 8, 10 and 12 tons/in.
The check that matters. Before a short bend at high tonnage, run both limits: (1) is the bend at least 60% of the side-frame span? and (2) does applied tons ÷ bend length in inches land under your tooling's derated rating? A 60-ton hit concentrated over a 6 in punch is 10 tons/in — inside a 12 tons/in tool at rating, but outside that same tool derated to 80% (9.6 tons/in), and far outside a 4 tons/in tool. That is the calculation that saves tooling.
Do not name a tooling line or load rating until its current manufacturer datasheet is attached to the product record; final tooling selection and tons-per-inch limits are quotation-specific

Sources: Jeelix, Press Brake Tooling Hardness · ADH Machine Tool, Press Brake Bending Capacity. Derated and 12-inch-bend values are UmproTech's arithmetic on those published ratings.