Hilti Welding Procedure Specification (WPS)

No. CSF-WPS F-BT-MR (EU-2)

Version: 01/2025-07-24

Stud Manufacturer and Testing

Stud Welding Process

Drawn-arc welding with shielding gas (783).

Welding current, welding time, lift, and protrusion are automatically adjusted by selecting the weld code H1, H2, H3, and H10. The weld code is stamped on the head of every stud and is given in the instructions for use of the stud.

Gas can: FX 3-GC.

Shielding gas (SG): According to ISO 14175: M21-ArC-18.

Gas flow rate: 3 l/min.

Preheat base material: > 0°C.

Welding positions: PA, PC, PE.

Earth clamp positioning: Minimum distance to stud welding position smin = 100 mm. For PC: Clamp must be positioned below stud welding position.

Stud Welding Equipment

Cordless stud fusion unit: FX 3-A.

Cordless stud fusion hand tool: FX 3-HT.

Stud holder: X-SH F3 M6-1/4", X-SH F3 M8-5/16", X-SH F3 M10-3/8", X-SH F3 M12-1/2".

Stud Material

EN steel designation: X6CrNiMoTi17-12-2, Number 1.4571 per EN 10088-3:2014.

ASTM designation: S31635, Type 316Ti per ASTM A240/A240-07 or ASTM A276-10.

Parent Material

Specification: Subgroups 1.1, 1.2, 1.3 and 2.1 according to CEN ISO/TR 15608, CEV ≤ 0.45 %.

Deoxidation method: Stud performance can only be assumed on fully killed steel.

Notes on Deoxidation: If the deoxidation method is not specified on the mill certificate, steel containing nitrogen binding elements in amounts sufficient to bind the available nitrogen (for example min. 0.02 % total aluminum) can be assessed as fully killed. The usual guideline is a minimum aluminum to nitrogen ratio of 2:1, when no other nitrogen binding elements are present. Such other elements and their content (% mass) shall be reported in the inspection document. In case of questions in assessing the suitability of parent material, contact Hilti for support.

Minimum thickness: Depends on coating, see allocation table at the end of this WPS.

Maximum thickness: 40 mm.

Shape: Flat steel.

Positioning in Base Material

Edge distance: cmin = 38 mm for thickness up to 30 mm, cmin = 76 mm for thickness > 30 mm.

Spacing between fasteners: smin = 35 mm.

Stud Welding Examination

Observation of: Hilti F-BT Visual Examination Catalogue, 2025-05-02, OTR/5724148/03.

Stud Welding Parameters

Parent Material Surface Preparation for F-BT-MR-SN Studs with Sealing Washer

Surface condition: Uncoated

Visualization: F-BT-MR-SN studs not applicable on uncoated steel.

Coated: Non-weldable primer, HDG coating, Duplex coating, Multi-layer coating.

Maximum coating thickness: 1000 μm.

Surface tool: FX 3-ST d20.

Surface preparation method: Surface preparation with appropriate tool. Prepared surface shall be free of any visible dirt, rust and coating. Surface to be welded shall be maintained dry and free from condensation. Maximum time permitted between preparation and welding: 2 hours.

Consideration of: F-BT Visual Examination Catalogue, 2025-05-02, OTR/5724148/03.

Parent Material Surface Preparation for F-BT-MR Studs without Sealing Washer

Surface condition: Uncoated or Weldable primer

Coated: Weldable and non-weldable primer, HDG coating, Duplex coating, Multi-layer coating.

Maximum coating thickness: 25 μm (Uncoated/Weldable primer), 1000 μm (Coated).

Surface tool: FX 3-ST d14 or grinding discs AG-D-SP or AG-D SPX (for uncoated/weldable primer); FX 3-ST d20 (for coated).

Workmanship: Surface preparation with appropriate tool. Surface shall be free of any visible dirt, rust and coating. Surface to be welded shall be maintained dry and free from condensation. Maximum time permitted between preparation and welding: 2 hours.

Consideration of: F-BT Visual Examination Catalogue, 2025-05-02, OTR/5724148/03.

Allocation Tables

F-BT-MR-SN studs with sealing washer for welding on coated parent material

Surface tool: FX 3-ST d20

F-BT-MR studs without sealing washer for welding on uncoated and coated parent material

Surface tool: FX 3-ST d14 or grinding discs AG-D-SP or AG-D SPX for uncoated steel or steel with weldable primer; FX 3-ST d20 for coated steel.