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S45C 40Cr Hadlock Nuts - M8~M48 Thread Sizes

Material: S45C,40Cr
Thread Size: M8 ~ M48
Surface Finish: Black，Galvanized

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Description

Key Attributes

Material: S45C,40Cr
Thread Size: M8 ~ M48
Surface Finish: Black，Galvanized

Specification

Hardlock Nut is composed of two upper and lower type self-tightening nuts, the upper nut has a bevel and the lower nut has a groove. When the two nuts are locked, the bevel and groove bite each other to form a conical structure.

Advantages of Hadlock Nuts OEM-Manufactured by Tianlong

1. Excellent anti-loosening performance of Hadlock nuts wholesaled by Tianlong

Hadlock nuts wholesaled by Tianlong adopt a unique two-piece self-tightening design, specifically the "upper nut with a bevel + lower nut with a groove" structure.

This structural advantage lies in that when locked, the bevel and groove bite each other to form a relatively stable conical structure, which is an ingenious design. Thanks to this design, the nuts possess extremely strong anti-loosening performance even during high-speed operation and severe vibration.

According to statistics, Hadlock nuts, as an important component of Japan's Shinkansen technology, have been widely used in China's high-speed rail tracks.

It is reported that approximately 50 million Hadlock nuts are used on China's high-speed rail tracks, accounting for 42% of the global market, which indicates that their performance has gained international recognition.

2. Premium and durable top-grade materials for Tianlong Hadlock nuts

Tianlong Hadlock nuts are made of high-quality S45C and 40Cr materials, which are excellent choices for high-strength materials. Both of these alloy steels have outstanding toughness and wear resistance.

Material Performance Comparison Table

Performance Indicator	S45C	40Cr	Q235 (Ordinary Carbon Steel)	20Cr (Low-Alloy Structural Steel)
Tensile Strength (MPa)	570-700	800-1000 (after quenching & tempering)	375-500	400-600
Impact Toughness (AKV, J)	20-30	40-60 (after quenching & tempering)	Relatively low (≈15-25)	Relatively high (≈40-60)
Hardness (HB)	170-217 (annealed) 200-250 (quenched & tempered)	187-229 (annealed) 241-341 (quenched & tempered)	131-187	179-229
Carbon Content (%)	0.42-0.48	0.37-0.44	0.14-0.22	0.17-0.24
Alloying Elements	Trace amounts of Si, Mn	Cr 0.8-1.1%	None	Cr 0.7-1.0%
Wear Resistance	Medium-high (carbon content enhances hardness)	High (Cr strengthens surface)	Low (easily worn)	Medium (lower carbon content)
Effect of Heat Treatment	Significant strength improvement after quenching & tempering	High strength and toughness after quenching + tempering	Cannot be significantly strengthened by heat treatment	High surface hardness after carburizing, but limited core strength
Typical Application Scenarios	General mechanical parts, shafts	High-strength fasteners, gears, shafts	Structural parts, ordinary bolts	Carburized parts (e.g., gears, piston pins)

3. A variety of specifications available

As a leading fastener manufacturer and supplier in China, the Hadlock nuts wholesaled by Tianlong come with multiple thread size options, ranging from M8 to M48.

In addition, their surface finishes offer two options: black and galvanized. You can purchase according to the construction conditions. Alternatively, you can contact us for custom services to perfectly meet the needs of your business scenarios.

4. Ideal for industries with strict requirements on fastening performance

Tianlong Hadlock nuts feature stable product quality and are highly recognized by enterprises in the global rail transit, heavy machinery, and automotive industries.