Weld studs

Bolte's steel 4.8 M6 examples use the same 030 suffix with different datums. Capacitor-discharge 11-06-030 and short-cycle 17-06-030 specify 30 mm before welding. Drawn-arc 41-06-030 specifies 30 mm after welding. The CD catalog estimates a 0.3 mm reduction and the short-cycle final length depends on energy. Verify installed height and weld condition for the actual procedure. CD type PT, PDF page 7, short-cycle type PS, PDF page 6, drawn-arc type RD, PDF page 11.

The weld end attaches to the host while the projecting thread receives a mating component. Bolte CD catalogue, PDF page 7, short-cycle catalogue, PDF page 6, drawn-arc catalogue, PDF page 11.

Drawn arc, short cycle, and capacitor discharge

In the drawn-arc sequence described by HBS, lifting the stud establishes a pilot arc; the main arc melts the stud end and receiving surface, and movement back toward the workpiece joins the molten regions. Short-cycle welding belongs to that drawn-arc family. HBS describes the same sequence with relatively higher current and shorter welding time, with a stated ceiling of 100 ms in its short-cycle explanation. This is a process description, not a weld schedule for every stud or sheet. HBS short-cycle process

Weld-pool protection is another distinction. Bolte's ceramic-ferrule drawn-arc catalogue describes a pressed-in aluminum ball serving as flux for its standard weld ends, with explicitly listed exceptions. The ceramic ferrule provides weld-pool backing. The same text describes a separate shielding-gas alternative using studs without that ball. The flux ball is consequently neither the stud's bulk material nor a feature of every drawn-arc stud. Bolte drawn-arc catalogue, PDF page 7

In HBS's tip-ignition capacitor-discharge (CD) description, a charged capacitor bank supplies a rapidly rising current that vaporizes the small ignition tip. The arc melts the stud end and receiving surface; forward motion brings the molten regions together. Its contact method starts with the tip against the workpiece, while the gap method starts with a defined separation and accelerates the stud toward it before tip contact. These are distinct initial mechanical conditions within CD welding. HBS CD process

Bolte's CD catalogue identifies a closely controlled welding pip, whereas its short-cycle catalogue identifies a conical welding face. Thus a small pip and a short-cycle cone are different ignition geometries, even when both studs have a flange and an M6 thread. Bolte CD catalogue, PDF page 5, short-cycle catalogue, PDF page 5

Exact M6 examples and length references

The following examples use Bolte steel 4.8 catalogue entries. All dimensions are in millimetres. Each example substitutes 030 into that family's published item-number pattern; the meaning of that length code differs between the families. These are catalogue identities and drawing dimensions, not a current controlled drawing or a measured weld result. CD type PT, PDF page 7, short-cycle type PS, PDF page 6, drawn-arc type RD, PDF page 11

The PT expression is approximate; the PS footnote expressly makes the final length dependent on energy. The RD catalogue instead defines nominal length as the length after welding and describes a diameter-dependent extra length before welding. Consequently, the common “030” suffix does not establish a common pre-weld length or a universal burn-off allowance. Bolte CD catalogue, PDF page 7, short-cycle catalogue, PDF page 6, drawn-arc catalogue, PDF pages 7 and 11

The RD fillet values are marked approximate. Bolte explains that ferrule geometry and welding parameters determine the actual fillet dimensions. The fillet is therefore different from the supplied stud's reduced tip diameter, and its catalogue envelope is not a guaranteed inspection limit for an unspecified weld. Bolte drawn-arc catalogue, PDF pages 8 and 11

Material, finish, and receiving surface

Bolte specifies 4–8 µm electrolytic copper plating as the standard surface protection for its steel 4.8 CD and short-cycle studs. Its drawn-arc ceramic-ferrule catalogue instead describes the usual supply condition as bright, with additional finish options. The latter catalogue assigns changed weld-tip tolerances to certain zinc-treated variants because those coatings are mechanically removed from the tip. The bright-stud tip tolerances differ from those assigned to these coated variants. This is a supplier-specific product condition, not a general surface-preparation instruction. Bolte CD catalogue, PDF page 5, short-cycle catalogue, PDF page 5, drawn-arc catalogue, PDF page 8

The selected CD PT M6 row also has separate A2-50, A5-50, AlMg3, and CuZn37 material/item-number columns. Those are stud alternatives in that row, not approval of every pairing with steel, stainless steel, aluminum, or brass receiving sheet. HBS identifies stud diameter and ignition geometry, component material and surface, sheet thickness, welding position, and weld-pool protection among the variables distinguishing process applications. A catalogue material label alone does not establish a compatible base-metal combination or a qualified joint. Bolte CD catalogue, PDF page 7, HBS process comparison

Electrical energy and mechanical motion

Welding current, arc duration, stored energy, and stud movement describe different quantities. Lift and plunge concern the stud's travel; spring pressure concerns the mechanical action bringing the molten regions together. Neither a current value nor a charging voltage specifies all of those conditions. HBS's CD explanation distinguishes charging the capacitor bank from tip ignition and the subsequent stud movement. HBS CD process, HBS short-cycle process

As a bounded electrical example, Bolte lists 132,000 µF capacitance, a 60–200 V charging-voltage range, and 2640 W·s charging energy for its LBS 130 CD unit. Using the ideal capacitor relation, the upper listed voltage gives:

C = 132,000 µF = 0.132 F
E = ½CV² = ½ × 0.132 × 200² = 2640 J = 2640 W·s

This calculation explains the relationship between the unit's listed electrical quantities. It is stored capacitor energy, not measured heat deposited in a particular weld, a recommended voltage for the M6 examples, or evidence of joint strength. Bolte LBS 130 technical data

Performance and evidence boundaries

The selected catalogue rows describe supplied geometry, materials, and approximate installed features. They provide no joint-specific tensile or shear result with a defined receiving plate, fixture, loading direction, and failure criterion. A steel 4.8 designation, a flange diameter, or a machine's charging energy therefore cannot by itself establish an allowable load for an assembled weld stud. HBS's process comparison likewise treats workpiece and process conditions as application variables. Bolte catalogue rows: CD page 7, short cycle page 6, drawn arc page 11, HBS process comparison

The inspected Bolte CD and short-cycle catalogues print “Last update 06/18”; the drawn-arc ceramic-ferrule catalogue prints “Last update 10/22.” These are the printed source identifiers, separate from PDF metadata and website retrieval. The cited files and web pages were accessed on October 31, 2026 (PDT); no publication date was established for the cited web articles. Full DIN EN ISO 13918, ISO 14555, and other referenced standards were not independently inspected. The sources do not establish a universal weld schedule, base-metal compatibility, joint qualification, or customer approval. CD catalogue, PDF page 24, short-cycle catalogue, PDF page 16, drawn-arc catalogue, PDF page 54

Related reference

Hardware and component references covers the broader assembly-process context.