ISO 7379 dimensions

 ISO 7379 Socket Head Shoulder Screw 

ISO 7379 Key Technical and Specification Summary

1. Product Overview & Core Characteristics

• Product: Hexagon socket head shoulder screws.

• Standard: ISO 7379:1983 (First edition).

• Primary Function: The unthreaded shoulder (d_s) is designed for precise alignment and bearing lateral (shear) loads in an assembly.

• Scope: Metric dimensions with nominal shoulder diameters from 6.5 mm to 25 mm.

• Critical Design Limitation: The standard explicitly notes that due to their configuration, these screws cannot be subjected to standard tensile testing. However, they must meet all other material and property requirements for their specified class.

2. Core Dimensional Specifications

• Shoulder Diameter (d_s): The critical locating dimension. For example, a nominal 10 mm shoulder has a min/max diameter of 9.951 mm / 9.987 mm.

• Thread Diameter (d): Paired with the shoulder. Example: a d_s of 10 mm corresponds to an M8 thread.

• Head Diameter (d_k): Values are given for both plain and knurled heads (knurled heads are slightly larger).

• Head Height (k), Wrench Size (s): Key dimensions for installation.

• Nominal Length (l): Refers to the shoulder length, ranging from 10 mm to 120 mm.

3. Geometrical Tolerances (Critical for Precision)

The concentricity and perpendicularity of the shoulder are vital for its locating function. The standard defines these tolerances in tables:

• Concentricity Tolerances: Based on diameters d_k, d_s, and d (e.g., tolerance based on d_k can be up to 0.78 mm).

• Perpendicularity Tolerances: Defined as values "X" (based on d_s) and "Y" (based on d).

• Shoulder Straightness: Defined by a formula (e.g., for d_s > 8mm: 0.0025 * l + 0.05 mm).

4. Material, Properties & Finish

• Material & Mechanical Properties:

  • Material: Steel.

  • Property class is exclusively 12.9 (per ISO 898-1). Important: This denotes material grade and other properties, not a verifiable tensile strength, as these screws are exempt from tensile testing.

• Thread Tolerance: 5g6g.

• Product Tolerance Grade: A (per ISO 4759-1).

• Surface Finish:

  • Shoulder: Surface roughness Ra ≤ 0.8 μm (per ISO 1302). Tolerances apply before plating.

  • General: Default black oxide finish. Electroplating per ISO 4042, other finishes by agreement.

5. Designation Example

• Designation is based on shoulder diameter and shoulder length, not thread size.

• Example: A screw with a 10 mm shoulder diameter and 40 mm shoulder length is designated:
  Hexagon socket head shoulder screw ISO 7379 - 10 × 40

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Summary: The ISO 7379 shoulder screw is defined by its precision-machined shoulder for alignment and shear load capacity. Key selection parameters are the shoulder diameter (d_s) and its tight geometrical tolerances. The fundamental design constraint is that it is not suitable for high tensile load applications.

 

Technical specifications table for shoulder bolts including shoulder diameter, head diameter, head height, thread dimensions, key engagement, and hexagon socket sizes. All measurements are in millimeters.

Shoulder Bolt Specifications Table

Nominal Size of Basic Shoulder Diameter	D Shoulder Diameter		A Head Diameter		H Head Height		D1 Thread Details		E Thread Length	T Key Engagement	J Hexagon Socket Size
	Shoulder Diameter		Head Diameter		Head Height		Nominal Thread	Threads Per Inch
	Max.	Min.	Max.	Min.	Max.	Min.	Thread Diameter
6	5.987	5.951	10	9.78	4.5	4.32	5	0.8	9.75	2.4	3
6.5	6.487	6.451	10	9.78	4.5	4.32	5	0.8	9.75	2.4	3
8	7.987	7.951	13	12.73	5.5	5.32	6	1	11.25	3.3	4
10	9.987	9.951	16	15.73	7	6.78	8	1.25	13.25	4.2	5
12	11.984	11.941	18	17.73	8	7.78	10	1.5	16.4	4.9	6
13	12.984	12.941	18	17.73	9	8.78	10	1.5	16.4	4.9	6
16	15.984	15.941	24	23.67	11	10.73	12	1.75	18.4	6.6	8
20	19.98	19.928	30	29.67	14	13.73	16	2	22.4	8.8	10
24	23.98	23.928	36	35.61	16	15.73	20	2.5	27.4	10	12
25	24.98	24.928	36	35.61	16	15.73	20	2.5	27.4	10	12

Technical specifications for shoulder bolts with detailed measurements in millimeters (mm).