STAUFF Stacking Bolt / Stacking Stud (Type AF – Twin Series)

Description

Operating Principles and Use

The STAUFF Stacking Bolt / Stacking Stud (Type AF – Twin Series) is a fundamental component in modular fastening systems for rigid pipes and hoses used in hydraulic and fluid power installations. The specific Type AF design is intended to enable the vertical stacking of multiple clamp levels belonging to the Twin Series, in accordance with DIN 3015, Part 3.

The Type AF stacking stud allows two or more clamp bodies to be installed one above the other while maintaining perfect axial and structural alignment of the assembly. To ensure secure and effective locking and prevent accidental loosening caused by mechanical loads or pressure pulsations, the stacking bolt must be used in combination with STAUFF Type SI or SIV safety locking plates.

Construction Features and Materials

STAUFF Type AF stacking studs are manufactured to strict dimensional tolerances to ensure complete interchangeability and reliable mechanical performance. Thread options include ISO metric threads, designated by the letter M, and Unified Coarse UNC threads, designated by the letter U.

Available material and surface-finish options include:

• W3 Carbon Steel: Zinc/nickel-plated for long-lasting corrosion protection in standard industrial environments.
• V2A Stainless Steel (Code W4): Corresponding to material grades 1.4301 / 1.4305 (AISI 304 / 303), suitable for moderately aggressive environments or industries with hygiene requirements.
• V4A Stainless Steel (Code W5): Corresponding to material grades 1.4401 / 1.4571 (AISI 316 / 316 Ti), specifically intended for highly corrosive environments, marine exposure or chemical-industry applications.

Compatibility and Dimensions

The stacking studs cover STAUFF Groups 1D to 5D, corresponding to DIN Groups 1 to 5 of the Twin Series. The range includes the following geometric and dimensional specifications:

• Group 1D (DIN 1): M6 or 1/4-20 UNC thread; spanner width (SW) of 11 mm for M6 or 7/16 in (11 mm / 0.43 in for UNC); total length L1 of 34 mm and 1.33 in respectively; shank length L2 of 20 mm and 0.78 in; minimum usable thread depth L3 of 12 mm and 0.47 in.
• Group 2D (DIN 2): M8 or 5/16-18 UNC thread; spanner width (SW) of 12 mm / 0.47 in; length L1 of 33 mm and 1.30 in; length L2 of 20 mm and 0.78 in; minimum thread depth L3 of 12 mm and 0.47 in.
• Group 3D (DIN 3): M8 or 5/16-18 UNC thread; spanner width (SW) of 12 mm / 0.47 in; length L1 of 44 mm and 1.73 in; length L2 of 29 mm and 1.14 in; minimum thread depth L3 of 12 mm and 0.47 in.
• Group 4D (DIN 4): M8 or 5/16-18 UNC thread; spanner width (SW) of 12 mm / 0.47 in; length L1 of 49 mm and 1.92 in; length L2 of 34 mm and 1.33 in; minimum thread depth L3 of 12 mm and 0.47 in.
• Group 5D (DIN 5): M8 or 5/16-18 UNC thread; spanner width (SW) of 12 mm / 0.47 in; length L1 of 61 mm and 2.40 in; length L2 of 46 mm and 1.81 in; minimum thread depth L3 of 12 mm and 0.47 in.

Summary Technical Table of the Main Features of the STAUFF Stacking Bolt / Stacking Stud (Type AF – Twin Series)

Product Codes