--- title: "Crane Steel Fabrication — Bridges & Girders to 50 t" description: "Crane steel fabrication from a contract manufacturer: crane bridges, girders, lifting beams & rope drums to 50 t — SAW-welded to DIN EN 1090-2 EXC3 in Lorch." url: "https://bock-gmbh.com/en/industries/crane-lifting-technology/" language: "en" index: "https://bock-gmbh.com/en/llms.txt" --- # Steel fabrication for crane & lifting technology: crane bridges, crane girders & rope drums up to 50 t As a contract manufacturer in steel fabrication we supply crane and lifting technology with load-bearing heavy-duty structures — crane bridges, crane girders, lifting beams, trolleys and rope drums up to 50 t part weight and 26 m in length, SAW-welded and finish-machined to DIN EN 1090-2 EXC3 in Lorch in the Stuttgart region. Heavy crane components up to 50 t part weight and 26 m in length — handled safely by the crane system with 25 t. Load-bearing crane bridges, crane girders and lifting beams in S355 and high-strength fine-grain structural steel up to S1100. Long load-bearing longitudinal seams are welded by the submerged arc process — uniform, documented and low in residual stress. Drum bodies for rope and hose guidance — vertical turning up to Ø 4,800 mm in diameter in-house. Lattice structures and boom components for mobile and gantry cranes — welded and machined on several faces. Load-bearing welded structures to EXC3, the highest execution class certified in practice — plus EN ISO 3834-2. ## Your supplier for crane & lifting technology Steel fabrication for crane manufacturing has to do more than carry load: crane bridges and crane girders are under constantly changing loads, every weld is built for fatigue strength, every hole pattern has to fit exactly over long distances. As a certified welding contractor we manufacture load-bearing crane components to your drawing — built for load capacity, dimensional accuracy and repeat accuracy in series as well as in single parts. The long load-bearing seams on crane girders and crane bridges are welded by the submerged arc process: high deposition rate, uniform bead appearance and complete documentation over the full component length. We then straighten the structures and machine hole patterns, connection and functional faces on our gantry milling machines up to 26 m. From the flame-cut blank through welding and CNC machining to shot blasting and industrial painting, everything is produced under one roof in Lorch in the Stuttgart region. That shortens lead times, avoids transport risks with heavy-duty components and secures complete material traceability to EN 10204. Submerged arc welding ## The limits for your crane component If your component lies within these limits we manufacture it completely in-house — from the SAW-welded crane girder to the turned rope drum, ready to install and corrosion-protected ex works Lorch. ## Typical components for crane & lifting technology To drawing and customer specification we manufacture, among others: ### Crane bridges Load-bearing bridge structures for overhead travelling and gantry cranes — SAW-welded, straightened and prepared for assembly. ### Crane girders & lifting beams Heavy-duty load-bearing elements in S355 and fine-grain structural steel — welded, straightened and with precisely fitting hole patterns. ### Crane trolleys & trolley frames Frames for hoisting and travelling gear as ready-to-install welded assemblies with machined functional faces. ### Rope drums & hose drums Turned and welded drum bodies for rope and hose guidance — vertical turning up to Ø 4,800 mm. ### Booms & lattice structures Lattice structures and boom components for mobile cranes — welded and machined on large-part machining centres. We manufacture further crane components to drawing — simply send us your documents. ## Materials & manufacturing depth for load-bearing crane components For crane manufacturing we mainly process structural steel S235/S355 and high-strength fine-grain structural steel up to S1100 — from a stock of over 40 material grades, with an inspection certificate 3.1 to EN 10204, from our own warehouse and cut to size. Long crane girders are SAW-welded, straightened and then machined — hole patterns, connection and functional faces on our gantry milling machines up to 26 m in length; welding and machining interlock without interface losses. The surface finishes the job: shot blasting and industrial painting to EN ISO 12944 in-house, so that load-bearing crane components reach assembly corrosion-protected. ## Long load-bearing seams: our SAW equipment for crane manufacturing Crane girders and crane bridges depend on the quality of their longitudinal seams. For these we rely on submerged arc welding systems — and inspect the seams in-house afterwards. Long longitudinal seams on crane girders Submerged arc welding with a high deposition rate — uniform, reproducible bead appearance over the full component length. Web-to-flange welds on heavy-duty girders Thick sections in fine-grain structural steel Multi-pass SAW seams in fine-grain structural steel up to S1100 — with a matched welding sequence against distortion. Flange plates on lifting beams Verifiable seam quality for EXC3 Welded to EN ISO 3834-2, inspected with MT by our own Level 2 inspectors in-house and with UT at our plant by our cooperation partner — including documentation for your verification records. Load-bearing butt and fillet welds ## Surface protection for load-bearing crane components After welding and machining we protect load-bearing crane components against corrosion in-house: ### Industrial painting in-house Shot blasting and coating to EN ISO 12944 in our own paint booth — reliable corrosion protection for load-bearing crane components. ### Corrosion protection for assembly Shot-blasted and painted, load-bearing crane components leave the Lorch plant ready to install and corrosion-protected. ## Impressions from crane manufacturing Real photographs from our shop floor in Lorch – from the welded flange blank for rope drums through tubular truss, cross member and box girder in machining to the finished painted girders and drum flange. In between, the portal frame with its pin joints in two views – being aligned and measured during assembly. ## One plant instead of five suppliers A crane girder passes through many steps — cutting, SAW welding, straightening, machining, testing, blasting, painting. Spread across several companies, this costs time, traceability and clear responsibility at every interface. With us it all stays under one roof. | Step in crane manufacturing | Distributed outsourcing | Bock — everything in-houseOne point of contact | | Long load-bearing longitudinal seams | External welding shop | SAW welding to EN ISO 3834-2 | | Turning rope drums & rings | Commission a turning shop | Vertical turning up to Ø 4,800 mm | | Seam inspection for EXC3 | External testing institute | NDT Level 2 (VT/PT/MT) in-house, UT via our cooperation partner | | Finish-machining girders | Contract machining shop | Gantry milling up to 26 m | | Corrosion protection | External paint shop | Blasting + painting EN ISO 12944 | | Heavy-load handling & loading | Freight forwarder logistics | Cranes up to 50 t in tandem · forklifts up to 16 t | ## Certified for load-bearing crane components Load-bearing crane components are manufactured to DIN EN 1090-2 EXC3 — the highest execution class certified in practice — and welded to EN ISO 3834-2 with comprehensive quality requirements. Every batch remains completely traceable via the material marking to EN 10204. ### Non-destructive testing in-house Dynamically loaded welds require reliable inspection evidence: - Visual, dye penetrant and magnetic particle testing (VT/PT/MT) are carried out by our own Level 2 inspectors to DIN EN ISO 9712 directly in our production — with no external waiting times. - Ultrasonic testing (UT) is carried out at our plant on a project basis by certified inspection personnel of our cooperation partner. Supplementary destructive tests such as tensile tests are arranged through accredited partner laboratories. Volumetric testing (radiographic testing RT, ultrasonic testing UT) is, insofar as commissioned, provided by qualified partners. Inspection scope and documentation are agreed to your specification — from the welding record to the inspection certificate 3.1. Non-destructive testing ## Why Bock as your supplier in crane & lifting technology - Heavy-load routine - Crane components up to 50 t part weight and 26 m in length — handled safely by the crane system with 25 t. - Long seams, little distortion - Submerged arc welding for load-bearing longitudinal seams plus flame straightening and vibration stress relief against distortion and residual stresses. - Welding + machining under one roof - Machining follows directly after welding: gantry milling up to 26 m, vertical turning up to Ø 4,800 mm — one point of contact, one plant. - Certified & traceable - DIN EN 1090-2 EXC3, EN ISO 3834-2, NDT Level 2 in-house and complete material marking to EN 10204. - Since 1963 - Over 63 years of heavy steel fabrication — today with more than 100 specialists on 14,000 m² of production space in Lorch in the Stuttgart region. Related industry: Conveying & recycling technology ## Frequently asked questions — crane & lifting technology ### Does Bock manufacture load-bearing crane bridges and crane girders to drawing? URL: https://bock-gmbh.com/en/industries/crane-lifting-technology/#kranbau-faq-fertigt-tragende-kranbruecken Yes. We manufacture crane bridges, crane girders, trolleys and lifting beams to your drawing in S355 and high-strength fine-grain structural steel — welded and machined to DIN EN 1090-2 EXC3, the highest execution class certified in practice. ### Up to what size and weight does Bock manufacture crane components? URL: https://bock-gmbh.com/en/industries/crane-lifting-technology/#kranbau-faq-groesse-welchem-gewicht-fertigt Up to 50 t part weight and 26 m component length. Handling is carried out by our crane system with 25 t; machining takes place on gantry milling machines in the same format. View our machinery ### Which materials are used in steel fabrication for crane manufacturing? URL: https://bock-gmbh.com/en/industries/crane-lifting-technology/#kranbau-faq-werkstoffe-kommen-stahlbau-kranbau Predominantly structural steel S355 and high-strength fine-grain structural steel up to S1100 — with an inspection certificate 3.1 to EN 10204 from our own stock, flame-cut up to 200 mm plate thickness. ### How are load-bearing welds in crane manufacturing inspected and documented? URL: https://bock-gmbh.com/en/industries/crane-lifting-technology/#kranbau-faq-tragende-schweissnaehte-kranbau-geprueft By visual, dye penetrant and magnetic particle testing (VT/PT/MT) carried out in-house by our own Level 2 inspectors to DIN EN ISO 9712; ultrasonic testing (UT) is carried out at our plant by our cooperation partner — documented for your EXC3 verification records. ### Does Bock also weld complete crane welded assemblies? URL: https://bock-gmbh.com/en/industries/crane-lifting-technology/#kranbau-faq-schweisst-komplette-kran Yes. From the single component to the ready-to-install welded assembly we manufacture crane girders, trolleys, trolley frames and lifting beams — welded, straightened, machined and, on request, blasted and painted. ### Does Bock turn rope drums and large rings in-house? URL: https://bock-gmbh.com/en/industries/crane-lifting-technology/#kranbau-faq-dreht-seiltrommeln-grosse-ringe Yes. Drum bodies for rope and hose guidance as well as large rings are turned on our vertical lathe up to Ø 4,800 mm in diameter and welded into the finished assembly — turning and welding interlock without outsourcing. CNC turning & vertical lathe ### Does Bock also supply crane manufacturers outside the Stuttgart region? URL: https://bock-gmbh.com/en/industries/crane-lifting-technology/#kranbau-faq-beliefert-kranhersteller-ausserhalb Yes. Manufacturing takes place in Lorch in the Stuttgart region; we supply crane manufacturers and plant builders throughout Germany and the DACH region. Heavy components are loaded by the crane system and heavy-duty forklifts up to 16 t. ## Request crane components to drawing Send us your drawings for crane bridges, crane girders, lifting beams or rope drums — we will assess feasibility, material availability and lead time and provide a no-obligation quote. Certified to DIN EN 1090-2 EXC3 · inspection certificate 3.1 to EN 10204.