Frequently Asked Questions

Fine blanking is a precision metal cutting process that uses three simultaneously acting forces — blanking force, V-ring force, and counter-pressure — to produce parts with 100% shear edges, tight tolerances, and flat surfaces in a single stroke. Unlike conventional stamping, which shears material with a single punch force and produces a fracture zone covering 30-70% of the edge, fine blanking forces the material to shear cleanly across the full thickness by holding it under compressive stress throughout the cut.

The V-ring — a raised ridge on the stinger plate — penetrates the material near the cutting edge before the punch descends, creating lateral compressive stress that prevents crack initiation. The counter-pressure force on the opposite side supports the material during shearing, preventing die-roll and maintaining flatness. The result is dimensional accuracy of IT7-8 (versus IT11-13 for conventional stamping), edge perpendicularity within 0.5 degrees, and surface finish that often eliminates the need for secondary machining operations such as milling, drilling, or reaming.

Choose fine blanking when your application demands one or more of the following: edge quality above 80% shear (safety-critical components, sealing surfaces, functional gear teeth), dimensional tolerance tighter than IT9, flatness under 0.1mm, production volume exceeding 10,000 parts per month, or elimination of secondary machining operations.

Fine blanking is particularly cost-effective when conventional stamping would require additional processes — broaching, milling, drilling, reaming, or shaving — to achieve the final part specification. The higher tooling cost of fine blanking (typically 2-3x conventional stamping dies) is recovered through eliminated secondary operations, reduced material waste, and higher per-part throughput. For low-volume applications under 5,000 parts per year or parts with simple geometries where edge quality is not critical, conventional stamping or laser cutting may be more economical.

Fine blanking is compatible with a wide range of metals. Carbon steels (C45, C60, CK45) are the most commonly fine-blanked materials, offering excellent shear characteristics and cost-effectiveness. Alloy steels such as 16MnCr5 and 20MnCr5 are standard for automotive gear and powertrain applications. High-strength low-alloy steels (S500MC, S700MC) are increasingly specified for structural components.

Stainless steels (304, 316L, 420) are fine-blanked for medical, food processing, and corrosion-resistant applications. Copper alloys (C5191 phosphor bronze, C5210) are used for electronic connectors and spring contacts. Spring steel (50CrV4) and electrical silicon steel are also commonly processed. Material thickness ranges from 0.3mm for thin electronic contacts up to 25mm for heavy structural plates, with the required tonnage scaling accordingly.

Fine blanking achieves dimensional tolerances of IT7-8 for blanking dimensions, compared to IT11-13 typical of conventional stamping. Flatness ranges from 0.02mm for thin materials (under 2mm) to 0.05mm for thicker materials (4-6mm), depending on the material grade and V-ring configuration.

Hole-to-profile positioning accuracy is typically plus or minus 0.02 to 0.05mm. Edge perpendicularity — the deviation of the sheared edge from true vertical — is maintained under 0.5 degrees. Edge surface finish typically ranges from Ra 0.4 to 1.6 micrometers. These tolerances are achievable consistently across production runs, with proper die maintenance and lubrication. For comparison, conventional stamping typically produces IT11-13 dimensional accuracy, 30-70% shear edge, and significantly more die-roll and taper.

Total tonnage for fine blanking is calculated as the sum of three forces: Blanking Force plus V-Ring Force plus Counter-Pressure. Blanking Force equals the cutting perimeter multiplied by material thickness multiplied by material shear strength, times a factor of 0.8 (accounting for the shearing angle).

For example, a part with 200mm perimeter in 4mm thick C45 steel (shear strength approximately 450 MPa) requires: 200 x 4 x 450 x 0.8 = 288kN, or roughly 29 tons. V-Ring Force is typically 20-50% of the Blanking Force, so 6-15 tons. Counter-Pressure is 10-25% of Blanking Force, so 3-7 tons. Total minimum tonnage: 38-51 tons. Add a 15-20% safety margin for the final machine selection. For this example, a 60-ton press would be specified. HS-FINEB provides free force calculations based on your part drawing.

Die life in fine blanking varies significantly based on die material, work material, and part complexity. D2 tool steel (DIN 1.2379) dies typically achieve 150,000 to 300,000 hits before the first regrind is needed. Powder metallurgy (PM) steel dies extend this to 300,000 to 600,000 hits. Carbide die inserts can exceed 1,000,000 hits under optimal conditions.

Die life is influenced by work material hardness and thickness, part geometry complexity, cutting clearance, lubrication quality, and press alignment. The regrind schedule typically removes 0.1 to 0.3mm of material per sharpening, and a die can typically be reground 5 to 15 times before retirement. Proper lubrication and regular press alignment checks can extend die life by 30-50%.

A complete fine blanking production line requires several auxiliary systems beyond the press itself. The line typically includes: a decoiler (rated for 5 to 15 ton coil weight), a straightener (5 to 9 rolls depending on material thickness), a servo feeder (with positioning accuracy of plus or minus 0.1mm), the fine blanking press, the die set, a deburring station (vibratory or brush type), a cleaning station, and an inspection station.

The press represents approximately 40% of the total line investment — the feeding, tooling, and finishing equipment constitute the other 60%. HS-FINEB provides complete line integration, ensuring that all auxiliary equipment is matched to the press capacity and part requirements, including coil width, material grade, and production speed.

Yes, existing dies can typically be used in HS-FINEB presses if the die envelope fits the press table dimensions and ram configuration. We provide standard die adapter plates and can modify shut height to accommodate different die designs.

To evaluate compatibility, we need: overall die dimensions (length, width, height), shut height, required V-ring force, required counter-pressure, and the number of stations if it is a progressive die. In most cases, adaptation is straightforward. If modifications are needed, our engineering team can design and manufacture transition plates, modified clamping systems, or adjusted pressure pin configurations.

The decision depends on the age and condition of the existing press. Refurbish if: the press is under 20 years old, the frame is structurally sound (verified by ultrasonic testing and dimensional inspection), and your budget is 30-45% of a new machine's cost. Buy new if: you have no existing press, you need the latest CNC capabilities, the old press frame has structural compromise (cracks, weld failures, or guideway damage beyond reconditioning), or your tonnage requirements have changed significantly.

Cost comparison for a 320T press: a new HS-FINEB HF-320 costs $200,000 to $400,000 depending on configuration, while a full refurbishment of an existing Feintool or Mori 320T costs $80,000 to $150,000. Timeline: 5 weeks for refurbishment versus 4-6 months for a new machine delivery. HS-FINEB provides honest assessments — if the frame is compromised, we will recommend replacement.

HS-FINEB's refurbishment service follows a comprehensive 7-point process:

(1) Hydraulic system — replacement of pump, valves, cylinders, and all seals with Bosch Rexroth and NOK components. (2) Guiding system — reconditioning of columns and bushings, restoration of parallelism to original specifications. (3) Electrical and PLC — upgrade to Siemens or Beckhoff control system with modern HMI. (4) Lubrication system — complete replacement of lines, pumps, and distribution blocks. (5) Safety systems — installation of light curtains, dual-hand operation, and emergency stop circuits to current standards. (6) Frame integrity — ultrasonic testing, welding repair if needed, and post-weld heat treatment. (7) Calibration and commissioning — full tonnage verification, parallelism measurement, and stroke accuracy testing.

All refurbishments include a 12-month warranty covering replaced components.

Delivery times vary by model and scope. Standard HF-series models (HF-200 through HF-650) have a manufacturing lead time of 4 to 6 months. Larger models (HF-700 through HF-1200) require 6 to 8 months due to custom engineering and heavier fabrication.

Refurbishment projects typically take 3 to 12 weeks depending on the scope of work and parts availability. Die design and manufacturing adds 8 to 16 weeks depending on complexity. Complete production line commissioning, including on-site installation, training, and process optimization, requires an additional 2 to 4 weeks on-site at your facility.

All new HS-FINEB presses include a 12-month warranty covering parts and labor. Refurbishment projects carry a 6-month warranty on replaced components. After-sales support includes: remote diagnosis (resolving 60-70% of faults without a site visit), spare parts supply from inventory (Bosch Rexroth hydraulic components, NOK seals, Siemens electrical parts, and standard wear items), on-site service within 48 hours for locations in Asia, comprehensive operator training at your facility, detailed maintenance manuals in English and Chinese, and PLC access for your engineering team to monitor and adjust process parameters.

HS-FINEB maintains a spare parts inventory for all models built in the last 15 years, ensuring long-term serviceability.