Lewei Hardware is a company with 20 years of experience in producing non standard hardware parts and standard fasteners.

The introduction of our grease nipples

2026-07-17

The introduction of our grease nipples

3. Specification introduction

Grease nipples are manufactured according to unified industrial standards. The three most authoritative global specifications are DIN 71412 (conical heavy-duty standard), DIN 3404 (metric straight thread standard), and SAE / BSP (imperial standard). Each standard defines different thread types, sealing structures and load levels. The dimension standard directly determines thread compatibility, mounting space, grease flow rate and service life. Correct standard matching is the core premise of leak-free installation and reliable lubrication.

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3.1 DIN 71412 (Core European Heavy-Duty Standard)

DIN 71412 is the German industrial standard specifically for conical seat grease nipples, widely recognized as the most reliable specification for harsh working conditions. Unlike ordinary straight-thread nipples, DIN 71412 adopts a conical self-sealing structure, which provides tighter sealing performance under high vibration and heavy load.

This standard classifies grease nipples into three geometric forms to fit all installation scenarios:

Form A – Straight (180°): Standard vertical type for open and accessible lubrication points.
Form B – 45° Angled: Used for positions with minor spatial obstruction.
Form C – 90° Angled: Designed for narrow, concealed and side-mounted lubrication points.

Application features: DIN 71412 nipples are commonly made of high-strength carbon steel with chrome plating. They are anti-loosening, leakage-proof and dust-resistant, and are the factory standard for European excavators, loaders, cranes, agricultural machinery and hydraulic systems.

3.2 DIN 3404 (General-Purpose Metric Standard)

DIN 3404 specifies straight parallel thread grease nipples for general light and medium-duty industrial equipment. It features simple structure, low cost and easy installation, suitable for machine tools, conveyors, fans and conventional mechanical bearings without severe vibration.

3.3 Metric Standard Sizes (Most Widely Used)

Metric grease nipples dominate European, Chinese, Japanese and most global engineering machinery, with complete standardized thread diameter and pitch parameters. Common specifications and applicable scenarios are listed below:

M4×0.7: Ultra-small size, compact structure. It is mainly used for precision miniature equipment, small robotic joints, precision instrument bearings and micro actuators with limited mounting space.
M5×0.8: Light-duty specification, widely applied in light hydraulic components, motorcycle parts, small agricultural machinery and precision automation equipment.
M6×1.0: The most universal light-to-medium size. It is standard for machine tools, automotive chassis parts, small conveyor rollers, household mechanical equipment and mainstream European/Japanese machinery.
M8×1.25: Medium general-purpose size. It covers most industrial equipment, conventional bearings, general mechanical hinges and medium-load automation production lines, featuring balanced structural strength and grease injection efficiency.
M10×1.5: Medium-heavy duty size. It is commonly equipped on construction machinery hinges, medium-sized crane joints, forklift movable parts and heavy-duty conveyor equipment.
M12×1.75: Heavy-duty mainstream specification. It is the standard size for excavators, loaders, bulldozers and large engineering machinery, suitable for high-load, high-vibration and severe working conditions.
M16×1.5 / M16×1.75: Extra-heavy size, specially used for large tower cranes, port machinery, heavy hydraulic equipment and oversized bearing lubrication points.

usually the common used are M6, M8, M10.

3.2 Imperial & BSP Standard Sizes

Imperial grease nipples are mainly adopted in American-made machinery, old industrial equipment and some marine devices. Typical mainstream sizes include:

1/4-28 UNC: Classic SAE standard size, widely used in North American trucks, construction equipment and automotive lubrication systems.
1/8 BSPP, 3/8 BSPP: British pipe thread standard, commonly matched with marine machinery, hydraulic pipelines and imported old-fashioned industrial equipment.

3.3 Structural Dimension Classification (Shape & Angle)

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In addition to thread sizes, grease nipples are also classified by installation angle and overall height, which are key dimensional indicators for on-site selection:

Straight type (180°): Vertical outlet, standard overall height, suitable for open and unobstructed lubrication points, convenient for vertical grease gun operation.
45° angled type: Inclined outlet, designed for lubrication points with slight space obstruction, solving the problem of insufficient vertical operation angle.
90° angled type: Horizontal outlet, specially used for narrow and deeply concealed installation positions, widely used for chassis side hinges and internal mechanical joints.

3.4 Size Selection Guidelines

For practical maintenance and replacement, size priority must follow the original equipment thread standard. Mismatched thread diameter or pitch will cause thread slipping, grease leakage and dust ingress. Small-size nipples apply to precision light-load equipment, while large metric and imperial heavy-duty specifications are reserved for high-load engineering and heavy industrial machinery. Meanwhile, the angle dimension should be selected according to the on-site operating space to ensure smooth grease gun docking and complete grease injection.

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