--- title: "Forged and Proof Machined Stainless Steel Bars, 120-550 mm" source: "https://www.laxconsteels.com/products/forged-proof-machined-bars/" description: "Forged and proof machined stainless steel bars 120 mm to 550 mm, rough turned to a proven defect free surface before final machining. Laxcon Steels, India." --- # Forged & Proof Machined Stainless Steel Bars Our integrated manufacturing edge gives us the ability to produce steel in a variety of finishes, surface options and profiles 120 mm - 550 mm Up to 6 metres ASTM A484, EN10060 [REQUEST A QUOTE](https://www.laxconsteels.com/contact/?product=forged-proof-machined-bars#form) ## Product Description Our largest bars, 120 mm to 550 mm, are supplied proof machined: rough turned below the outer skin so the surface is proven clean and free of defects before the customer's final machining. Proof machined bars carry a superior, inspected surface and cater to the biggest sizes in our [round bar range](https://www.laxconsteels.com/products/stainless-steel-round-bars/). Weight per metre at these diameters is worked out by the [weight calculator](https://www.laxconsteels.com/weight-calculator/), and grade chemistry is in the [grade reference](https://www.laxconsteels.com/grades/). ![Proof machined stainless steel bars produced by Laxcon Steels](https://www.laxconsteels.com/images/products/stainless-steel-proof-machined-bars.webp) ## Supply Conditions | Property | Value | | --- | --- | | Size range | 120 mm - 550 mm (4-3/4" - 21-2/3") | | Length | Up to 6 metres | | Tolerances | ASTM A484, EN10060 | | Heat Treatment | Soft Annealed, Solution Annealed, Normalizing, Quenched & Tempered | - Ultrasonic tested - Free from Radioactive elements, Mercury & Lead contamination - Grade confirmation through PMI testing with Handheld Spectrometers - Weight per metre for every listed size: [metal weight calculator](https://www.laxconsteels.com/weight-calculator/) ## Governing standards | Property | Value | | --- | --- | | EN 10088-3 | Stainless steels: technical delivery conditions for semi-finished products, bars, rods, wire, sections and bright products for general purposes. Composition, heat treatment condition and mechanical properties per grade. | | ASTM A276/A276M | Stainless steel bars and shapes: composition, condition, mechanical properties and finish designations for hot-finished and cold-finished bar. | | ASTM A484/A484M | General requirements for stainless steel bars, billets and forgings: permissible variations in dimensions, straightness, weight and length, and the test and marking requirements every bar order inherits. | | ASTM A473 | Stainless steel forgings. | | ASTM A314 | Stainless steel billets and bars for forging. | | EN 10204 | Metallic products, types of inspection documents: the 2.2 test report and the 3.1 and 3.2 inspection certificates a purchase order can call for. | ## Weight per metre | Diameter (mm) | kg per metre | Metres per tonne | | --- | --- | --- | | 120 | 89.35 | 11.2 | | 150 | 139.61 | 7.2 | | 200 | 248.20 | 4.0 | | 250 | 387.81 | 2.6 | | 300 | 558.45 | 1.8 | | 350 | 760.11 | 1.3 | | 400 | 992.80 | 1.0 | | 450 | 1,256.51 | 0.8 | | 500 | 1,551.25 | 0.6 | | 550 | 1,877.01 | 0.5 | Density 7.90 g/cm³ (d² x 0.006205). A 304 bar at 7.93 g/cm³ runs 0.4 percent heavier, a 316 bar at 7.98 g/cm³ 1 percent heavier. Sizes are the published range at the nominal diameters shown. ## Proof machining Above 120 mm a stainless bar is forged from an ingot or a bloom rather than rolled, and the forged surface carries scale, a decarburised skin and the small laps and folds of the hammer. Proof machining turns that skin off, usually 3 to 6 mm on diameter, so that the surface the customer receives has been seen and inspected in the bright and any defect that would otherwise appear halfway through a customer's machining programme is found at the works. The bar is then ultrasonically tested through a clean surface, which is the other reason the skin comes off. The condition is chosen for the machining that follows: soft annealed or solution annealed for the austenitic grades, normalised or quenched and tempered for the martensitic and alloy grades. At 550 mm a metre of bar weighs 1.88 tonnes, so lengths are supplied cut to the customer's piece length rather than at the 6 metre maximum. ## Forged bar against hot rolled bar The [hot rolled round bar](https://www.laxconsteels.com/products/hot-rolled-round-bars/) covers 16 to 125 mm from the rolling mill; the forged and proof machined bar covers 120 to 550 mm from the press. The overlap at 120 to 125 mm is decided by the grade and the end use: a rolled bar is the lower-cost route, a forged bar has the higher reduction ratio that a large shaft or a pressure part with a through-thickness property requirement is specified on. The [forging quality ingot](https://www.laxconsteels.com/products/forging-quality-ingots/) is the starting stock for both this page and the customer's own forge. ## Frequently Asked Questions ### What proof-machined bar sizes does Laxcon publish? Laxcon publishes proof machined bars from 120 mm to 550 mm diameter, in lengths up to 6 metres. ### Which tolerances and heat treatments are available? Proof machined bars can be supplied to ASTM A484 or EN 10060 tolerances in soft-annealed, solution-annealed, normalized, quenched or tempered condition. ### Are proof-machined bars ultrasonically tested? The published supply condition for proof machined bars includes ultrasonic testing. Grade confirmation through handheld PMI is also listed. ### How can proof-machined stainless steel bars be packed and traced? Laxcon packs proof machined stainless steel bars in standard bundles of 500 to 1,000 kg with HDPE or LDPE wrapping and two lifting slings. ISPM 15 wooden boxes and fibre-tube packing are available, and every bundle is marked with heat number, grade, size, and net and gross weight. ### What should an RFQ for proof-machined stainless steel bars include? An enquiry for proof machined stainless steel bars is quotable when it states the grade, governing standard, metric size or profile, tolerance, finish or heat-treatment condition, length, quantity, test or inspection requirement, and delivery destination. [Search 500+ grades](https://www.laxconsteels.com/grades/) [Compare equivalents](https://www.laxconsteels.com/grades/equivalents/) [Check weight charts](https://www.laxconsteels.com/weight-charts/) [Review quality](https://www.laxconsteels.com/quality/) [Send the RFQ](https://www.laxconsteels.com/contact/?product=forged-proof-machined-bars)