Tensile Testing for Recycling and Upcycling in the Circular Economy

How Do You Prepare Forged Tensile Specimens For ASTM E8 Testing?

Start by selecting the sampling direction specified on the drawing, usually parallel to the primary grain flow of the forging. Remove surface scale and decarburized layers before laying out the blank. For common ASTM E8 subsize flats, target a 2.00 in (50 mm) gage length with about 0.50 in (12.5 mm) gage width, or apply the 4D rule for round bars. Keep the reduced section centered and coplanar with the forging’s working direction to avoid mixed microstructures. Machine the profile on a dedicated specimen preparation system. Use flood coolant and conservative finishing parameters to avoid work hardening, for example 0.010 in (0.25 mm) radial depth of cut with 0.002–0.006 in/rev (0.05–0.15 mm/rev) feed on steels. Finish the gage length longitudinally and aim for Ra ≤ 32 µin (0.8 µm). Break edges lightly, about 0.010 in (0.25 mm), to prevent nicks that can trigger early fracture. Before testing, mark two punch or scribe marks 2.00 in (50 mm) apart, verify straightness within roughly 0.002 in per 6 in (0.03 mm per 150 mm), and confirm grip sections match the selected ASTM E8 specimen type. During mounting, align the shoulders in the grips and tighten evenly to minimize bending from off-axis loading. If you want repeatable, standards-based coupon machining with built-in specimen libraries, you can review Flat Tensile Test Sample Preparation Machines on the product page.

What Are The First Steps For Tensile Testing Of Forged Parts In Quality Control?

Begin with a representative sampling plan from the forging that matches the thermal and deformation history. Machine a standardized coupon per ASTM E8 or ISO 6892-1. For steels, a common round geometry is 0.500 in (12.7 mm) diameter with a 2.00 in (50.8 mm) gauge length. Choose flat or round based on available section thickness and grain flow direction. Maintain axial machining marks, hold key dimensions within about ±0.001 in (±0.025 mm), deburr shoulders, and avoid transverse scratches that could trigger premature necking. Finish the gauge section near 63 µin Ra (1.6 µm) and mark the gauge length at 2.00 in (50.8 mm). Record melt, heat, lot, and orientation so results can be traced back to the forging sequence and heat treatment. On the UTM, use self-aligning or symmetric wedge grips with roughly 1.0–1.5 in (25–38 mm) of grip engagement. Mount a 2.00 in (50.8 mm) extensometer, apply a small seating preload around 10–20 lbf (45–90 N), and test at 68–77 °F (20–25 °C). Set the speed or strain-rate control to the range specified by ASTM E8 for yield determination, then transition to the specified rate for elongation and UTS. If you observe grip slippage or bending from unequal extensometer readings, correct the setup before running production lots. If you would like to review UTM frames and controls for metals testing, you can explore details on the Tensile Testing Equipment equipment page.

How Should Forging Labs Size UTM Capacity And Select Grips For Tensile Testing?

Start with a simple load estimate. Multiply expected ultimate tensile strength by the net cross-sectional area. For a 1.00 in × 0.25 in flat coupon, area is 0.25 in². At 120 ksi, the expected peak load is about 30 kip. Choose a frame with at least 1.3 to 1.5 times that value, so a 50 kip machine is appropriate. In metric, a 25.4 mm × 6.35 mm section is 161 mm² at roughly 830 MPa, which yields about 133 kN, so a 250 kN frame fits. Select the drive based on load and duty cycle. Electromechanical frames cover light to mid loads with fine speed control. For heavy forgings above roughly 220 kip (1 MN) or long test sequences, hydraulic frames are common. Match grips to the surface and geometry. Self-tightening wedge or hydraulic wedge grips with serrated faces hold hot-worked materials well across 0.125 to 1.00 in (3.2 to 25.4 mm) thickness ranges. Control alignment and measurement quality. Verify axiality per ASTM E1012, use the correct gauge length such as 2.0 in (50 mm) for E8 specimens, and select an extensometer with adequate travel. Remove scale and burrs, then machine or longitudinally polish the gauge section to avoid stress risers. If you would like to review frame ranges, grips, and extensometry options, you can explore details on the All Tensile Testing Equipment page.

How Do I Choose UTM Type And Capacity For Tensile Testing Of Forged Parts?

Select the frame by matching load range and control needs. Electro-mechanical machines excel at precise crosshead and strain-rate control for low to mid loads, ideal for sub-size coupons and routine alloy checks. Servo-hydraulic machines handle high-capacity work and thick sections, with comfortable headroom near 135 kip (600 kN) or 225 kip (1000 kN). If the expected peak load often exceeds about 60 kip (270 kN), hydraulic usually offers better durability and grip force for large forgings. Size capacity from a quick calculation: capacity ≥ UTS × area, then add margin for off-axis effects and grip friction. Example: a 0.50 in (12.7 mm) round at 120 ksi (830 MPa) has 0.196 in² (126.5 mm²) area, predicted peak about 23.6 kip (105 kN). With a 30% margin, select at least 31 kip (138 kN). For shafts with localized hardening or variable section, consider a 50% margin. Match accessories to the standard and geometry. For ASTM E8/E8M, use the specified gauge length, commonly 2.0 in (50 mm), and verify axial alignment per ASTM E1012. Choose wedge or hydraulic grips rated above machine capacity and sized to the grip section. If machining marks remain, apply longitudinal polishing to the gauge to reduce stress raisers before testing. If you would like to compare frame types, capacities, and accessories, you can review details on the Tensile Testing Equipment equipment page.

How Should Forging Labs Size a UTM and Specimen Preparation Setup for Tensile QA?

Start with load. Multiply the highest expected ultimate tensile strength by the largest test cross-section you plan to machine, then add a safety margin for strain hardening and grip friction. Example: a 0.505 in (12.83 mm) round per ASTM E8 has about 0.200 in² (129 mm²) area. At 150 ksi (1,034 MPa), peak load is roughly 30,000 lbf (133 kN). A 50 kip (222 kN) frame handles most steels. For oversized coupons or subcomponent pulls, plan for 135 kip (600 kN) to 225 kip (1,000 kN) hydraulic frames. Specimen preparation drives repeatability. A CNC system that holds dimensional tolerance to ±0.0003 in (±0.008 mm) and machines up to 60 HRC cuts down rework and out-of-spec blanks. For surface integrity, a longitudinal polisher set for length, speed, and pressure removes circumferential tool marks and helps maintain finishes near 32 µin Ra (0.8 µm) before testing. During testing, follow ASTM E8 or ISO 6892-1 for gauge length, speed or strain-rate control, and extensometer use, commonly 2 in (50 mm). Record heat number, orientation, and heat-treat batch with every pull so outliers can be traced to forging or thermal variables, not preparation artifacts. You can review frame capacities and control options on the Tensile Testing Equipment equipment page.

Tensile Testing for Recycling and Upcycling in the Circular Economy

What is Recycling and Upcycling?

Material Recycling

Material Upcycling

Why Tensile Testing Matters in Recycling and Upcycling

Assuring Material Quality in Recycling

Supporting Upcycling Innovation

Advancing Circular Economy Goals

Overcoming Challenges in Tensile Testing for Recycling and Upcycling

Reliable Equipment for Tensile Testing in Recycling and Upcycling

Achieving the Circular Economy Through Reliable Tensile Testing

How Do You Prepare Forged Tensile Specimens For ASTM E8 Testing?

What Are The First Steps For Tensile Testing Of Forged Parts In Quality Control?

How Should Forging Labs Size UTM Capacity And Select Grips For Tensile Testing?

How Do I Choose UTM Type And Capacity For Tensile Testing Of Forged Parts?

How Should Forging Labs Size a UTM and Specimen Preparation Setup for Tensile QA?