GB/T 36253-2018 (English Version)

Standard No.: GB/T 36253-2018
Language: Chinese, Available in English version
Release Date: 2018
Published By: General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
Latest: GB/T 36253-2018

Scope: This standard specifies the structure, dimensions and requirements of MJ threaded aluminum alloy blind hole self-locking inserts for aviation. This standard applies to MJ threaded aluminum alloy blind hole self-locking inserts for aviation.

Introduction

GB/T 36253—2018 Aviation MIJ Threaded Aluminum Alloy Blind Hole Self-locking Inserts Standard Overview

This standard specifies in detail the structure, dimensions and requirements of aviation MJ threaded aluminum alloy blind hole self-locking inserts, which is suitable for the demand for high-performance fasteners in the aerospace field. This standard combines MJ thread technology with aluminum alloy material properties to ensure reliability and durability in extreme environments.

Main Technical Requirements

Item	Material Requirements	Surface Treatment	Thread Parameters	Performance Index
Material	Aluminum Alloy 2024 (EN 3347)	Anodizing (ISO 8076)	GJB 3.2A MJ Thread Standard	Meet HB 7595 Temperature Requirements
Dimensional Parameters	d1 Tolerance Range	H and D Tolerance Control	Effective Length of L	Minimum H1 and H2 values

Dimension and tolerance analysis

According to Table 1, inlays with different diameters have strict dimensional tolerance requirements:

MJ3X0.5-4H6H: Applicable to d1=9, 12, 15, 19, 22, 25 mm, H=12 mm, D=14.2 mm, L=9.3 mm.
MJ4X0.7-4H6H: Applicable to d1=12, 15, 19, 22, 25 mm, H=15 mm, D=14.2 mm, L=9.3 mm.
MJ5X0.8-4H6H: Applicable to d1=15, 19, 22, 25 mm, H=17.5 mm, D=17.5 mm, L=11.9 mm.
MJ6X1-4H5H: Applicable to d1=15, 19, 22, 25 mm, H=19 mm, D=17.5 mm, L=11.9 mm.

Material and Surface Treatment

Aluminum Alloy 2024 (EN 3347) is the core material of this standard and is widely used in the aerospace field due to its high strength and corrosion resistance. After anodizing (ISO 8076), the alloy forms a chromic acid coating on the surface, providing additional corrosion protection and is suitable for working environments with temperatures not exceeding 425°C.

Implementation Advice

In actual applications, it is recommended to follow the following steps to ensure compliance with GB/T 36253—2018 standard:

Select the appropriate specification model: Select the appropriate diameter specification (such as 030, 040, 050, 060) according to assembly requirements and environmental conditions.
Verify material and surface treatment: Ensure that aluminum alloy 2024 that complies with EN 3347 is used and anodized to meet ISO 8076 requirements.
Check thread parameters: Confirm that the thread meets the GJB 3.2A standard, especially the effective length and tolerance range.
Performance testing: including torque retention at high temperatures, corrosion resistance and mechanical strength testing.

GB/T 36253-2018 history

2018 GB/T 36253-2018 Inserts for aviation, self-locking with MJ threads, closed type, in aluminium alloy