High Tension Round Link Chain For Mining

Technical Advantages

• Superior Case Hardening for Abrasive Environments: Mining chains constantly rub against abrasive coal, rock, and steel pans. JULI chains undergo a proprietary induction heat-treatment process that creates a dual-zone microstructure: a rock-hard outer shell to resist wear, and a highly resilient, tough inner core to prevent sudden brittle fractures.

• Exceptional Fatigue & Shock Resistance: Underground mining involves constant starting, stopping, and jamming. Our chains are engineered with a high elastic limit, meaning they absorb the immense energy of sudden blockages without suffering permanent elongation or micro-cracking.

• Perfect Pitch Accuracy for Sprocket Engagement: Inconsistent chain pitch causes accelerated sprocket wear and chain jumping. Utilizing fully automated CNC calibrated bending and welding lines, JULI guarantees strict dimensional tolerances, ensuring seamless engagement with conveyor drive sprockets.

• Strict Mechanical Calibration & Proof Testing: Every meter of our mining chain undergoes a 100% proof load test at 60% of its minimum breaking force, followed by destructive sampling for impact toughness and macro-structural analysis in our CNAS-approved laboratory.

Applications

• Armored Face Conveyors (AFC): Twin-strand and triple-strand chain configurations for scraping coal across the longwall face.

• Beam Stage Loaders (BSL): Heavy-duty transition chains transferring crushed coal from the face to the main conveyor belt.

• Coal Plows & Shearer Haulage: High-tension pulling chains that guide continuous mining machines along the seam.

• Heavy-Duty Industrial Bucket Elevators: Vertical transport of highly abrasive raw ores, cement, and minerals.

Core Parameters

• Quality grade: B, C
• Marks: Quality grade mark, such as “JLB/JLC”.
• Production range is Ф18-Ф48mm.
• Standards: Produced in accordance with the standard of GB/T12718-2009.
• Certifications: Mining chain obtained MA certificate. Lifting chain obtained CE certificate
• Equipment: The chain manufacturing facility is equipped with chain-making machines, flash butt welders, and tensile testing machines from WAFIOS (Germany), as well as SPECTROMAXx metallurgical analysis spectrometers. Driven by a continuously expanding market share in recent years, the facility has established 17 chain production lines, 3 chain sling assembly lines, and 2 chain link welding lines.

Specifications

High Tension Round Link Chain For Mining
	Diameter of Link d (mm)	Pitch P（t）	Width (mm)		Radius of Arc r(mm)	Diameter at The Weld (mm)		Weight/m (kg/m)	Testing Load       (KN)	Min.Breaking Load     (KN)	Working Load (KN)	Quality grade
			Minimum Inner Width a	Maximum   Extemal Width b		Diameter d1max	Length e
	18	64	21	60	28	19.5	13	6.6	260	320	200	B
									330	410	256	C
	22	86	26	74	34	23.5	15.5	9.5	380	480	300	B
									490	610	381	C
	24	86	28	79	37	26	17	11.6	460	570	356	B
									580	720	450	C
	26	92	30	86	40	28	18	13.7	540	670	418	B
									680	850	531	C
	30	108	34	98	46	32.5	21	18	900	1130	706	C
									1130	1410	881	D
	34	126	38	109	52	36.5	23.8	22.7	1160	1450	906	C
									1450	1810	1130	D
	38	126	42	121	58	41	27	30	1450	1810	1131	C
	38	137	42	121	58	41	27	29	1450	1810	1131	C
	38	146	42	121	58	41	27	27.6	1450	1810	1131	C
	42	146	46	133	64	45	30	36	1770	2220	1388	C
	42	152	46	133	64	45	30	35.3	1770	2220	1388	C
	48	152	62	163	80	51	34.3	45.7	2320	2900	1813	C
	1. Application area: Mine scraper   conveyor, scraper loader,plow and other equipment.
	2. Quality grade: B,C
	3. Marks: Quality grade mark,   such as “JLB\JLC”. Safety logo “MA”、“KA”.

Customization Options

JULI mining chains are engineered to match your specific conveyor design and comply with global mining standards.

• Size Range: Bar diameters from 14mm up to 52mm+ (including standard 18mm, 22mm, 26mm, and 30mm profiles).

• Material Grade: High-tensile micro-alloy steel available in Grade 2, Grade 3, and Grade C.

• Compliance Standards: Fully certified to DIN 22252-1, DIN 22252-2, and ISO 614 for seamless sprocket alignment.

• Surface Finish: Black Oxide, Natural Oiled, Zinc Coated, or Phosphated anti-corrosion barriers.

• Quality Verification: 100% NDT weld inspection, Charpy V-Notch impact testing, and calibrated elongation analysis.

Performance Comparison

To assist engineers in making technical decisions within seconds, we present the unique mechanical performance of mining round link chains under extreme operating conditions:

Performance Metric	JULI Mining Round Link Chain	Standard Lifting Chain	Commercial Transmission Chain
Primary Application	Underground Scraper Conveyors / Heavy Mining	Overhead Lifting & Rigging	Light-Duty Drive Systems
Dynamic Shock Absorption	Exceptional (Engineered for coal impact)	High	Low
Surface Hardness (Wear)	Deep Case-Hardened (Resists abrasive rock)	Through-Hardened	Standard Carburized
Fatigue Life (Cycles)	Highest (Tested under continuous tension)	Standard	Low
Corrosion/Acid Resistance	High (Formulated for underground mine water)	Moderate	Poor

Learn more about rigging chains from Julisling.

FAQ

Q: What is the difference between Grade 3 and Grade C mining chains?

A: Grade 3 is the standard high-tensile mining chain defined by DIN 22252, ideal for general underground conveying. Grade C utilizes micro-alloyed steel with superior temper resistance and higher tensile properties, specifically engineered for ultra-heavy-lift longwall operations and highly corrosive mine environments.

Q: How does JULI prevent hydrogen embrittlement in underground chains?

A: Underground mines often have acidic water that can cause hydrogen-induced cracking. JULI eliminates this risk through precise chemical composition control (low sulfur and phosphorus content) combined with advanced stress-relieving tempering processes post-welding.

Q: Can you provide matching master links, connectors, and flight bars?

A: Yes. JULI provides a complete conveyor rigging system, including high-strength shackle-type connectors, highly articulated block links, and custom flight bars to match your scraper conveyor design.