L Type Jaw Coupling Guide: Powder Metallurgy, Maintenance-Free, 0.05-75 N·m

L Type Jaw Coupling Selection Guide – Cost-Effective Couplings for Wave Soldering Machines

L Type jaw couplings (also known as L series or elastic jaw couplings) are among the most economical and widely used flexible couplings for light to medium-duty industrial applications. With a simple three-piece design – two powder metallurgy hubs and one rubber spider – they offer an excellent balance of cost, performance, and ease of maintenance.

This guide explains how L Type couplings work, why they are ideal for wave soldering machines, and how to select the right model for your application.

1. What Is an L Type Jaw Coupling?

An L Type jaw coupling consists of:

Two powder metallurgy (sintered iron) hubs – lightweight, precision-made, cost-effective
One rubber spider (NBR/nitrile butadiene rubber) – resilient, elastic, and oil-resistant

The spider transmits torque while absorbing shock, dampening vibration, and compensating for misalignment. The simple three-piece design allows for quick assembly and disassembly without special tools .

2. Key Advantages of L Type Couplings

Advantage	Benefit
Cost-effective	Powder metallurgy hubs – economical for high-volume applications
Lightweight	Low inertia – suitable for high-speed applications
Maintenance-free	No lubrication required – reduces operating costs
Easy assembly	Three-piece design – no special tools required
Fail-safe	Continues to operate if spider fails
Industry standard	Interchangeable with Lovejoy, Martin, Browning
Oil & dirt resistant	Suitable for harsh environments

3. Why L Type Couplings Are Ideal for Wave Soldering Machines

Wave soldering machines are used in large-scale electronic assembly processes to solder components to PCBs. L Type couplings are commonly used in these machines:

Requirement	How L Type Coupling Meets It
Cost-effective	Powder metallurgy hubs – economical for production equipment
Lightweight	Low inertia – suitable for high-speed conveyor drives
Maintenance-free	No lubrication – reduces downtime
Easy maintenance	Quick spider replacement – minimizes production stops
Vibration damping	Rubber spider – protects sensitive electronics
Fail-safe	Continues to operate if spider fails – prevents production stops

✅ Commonly used in wave soldering and reflow soldering equipment – L070 and L075 are popular sizes .

4. Material Selection – Powder Metallurgy vs Cast Iron

Standard L Type coupling hub materials are:

Size Range	Hub Material
L035 to L190	Powder metallurgy (sintered iron)
L225 to L276	Cast iron

✅ Powder metallurgy provides a cost-effective, lightweight solution for most applications. Cast iron is used for larger, higher-torque models.

5. Spider Material Options

Spider Material	Torque	Temperature Range	Best For
NBR Rubber (Standard)	Baseline	-40°C to 100°C	General purpose, oil resistance, vibration damping
Urethane	Higher	Limited	Higher torque, less damping
Hytrel®	Up to 3x NBR	-51°C to 121°C	High torque, high temperature, oil/chemical resistance
Bronze	Up to 3x NBR	-40°C to 232°C	Low speed (≤250 RPM), extreme conditions

✅ The standard NBR rubber spider is recommended for most applications requiring vibration damping and oil resistance.

Model	Min. Torque	Max. Torque	Max. Speed (rpm)	D (mm)	L0 (mm)	L1 (mm)	L2 (mm)	Min. (mm)	Max. (mm)	d (mm)	Moment of Inertia (kgf·cm²)	Weight (kg)
L‑035	0.05	0.15	6000	16.1	20.5	6.5	7.5	4	8	0.1	0.04	0.04
L‑050	0.15	0.45	4500	27	43.2	15.5	12.2	6	16	1	0.14	0.14
L‑070	0.3	0.9	3600	35	49.2	18.5	12.2	6	20	3.3	0.27	0.27
L‑075	0.5	1.5	3600	45	54.4	21	12.4	8	26	9.1	0.45	0.45
L‑090	0.8	2.4	3000	54	55	21	13	10	28	15	0.6	0.6
L‑095	1	3	3000	55	61	24	13	10	28	17	0.7	0.7
L‑099	2	6	3000	66	73	30	18	12	36	42	1.4	1.4
L‑100	2.5	7.5	3000	66	88	35	18	12	36	43	1.5	1.5
L‑110	5	15	2500	85	110	44	22	12	48	147	3	3
L‑150	10	30	2500	96	118.5	46	26.5	16	48	258	4	4
L‑190	15	45	2000	115	138.5	56	26.5	16	58	628	6.9	6.9
L‑225	20	60	2000	127	152.5	63.5	26.5	18	60	1685	40.45	40.45
L‑276	25	75	2000	157	200	79	41	22	73	5265	21.36	21.36

7. Installation & Maintenance Tips

Clean shafts and bores – Remove oil, grease, and debris before assembly.
Check alignment – Even with misalignment compensation, keep within recommended limits.
Install spider correctly – Ensure proper fit between the two hubs.
No lubrication required – Spider is self-lubricating .
Inspect spider periodically – Replace if cracked, worn, or deformed.
Fail-safe backup – If spider fails, schedule prompt replacement .

8. Selection Checklist

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Model: L035 to L276 – select based on torque and bore requirements
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Hub material: Powder metallurgy (L035-L190) or cast iron (L225-L276)
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Spider material: NBR rubber (standard) – oil-resistant, vibration damping
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Spider hardness: 80A, 55D, or 90-95A – match your torque/damping needs
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Bore size: Match your shaft diameters – custom bores available
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Temperature: -40°C to 100°C – verify operating range
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Application: Wave soldering, conveyors, pumps, compressors
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Maintenance: Maintenance-free – no lubrication required

9. Conclusion

The L Type elastic jaw coupling from Apex Coupling offers the perfect combination of cost-effectiveness, lightweight construction, and maintenance-free operation for wave soldering machines and general industrial applications. With powder metallurgy hubs, NBR rubber spider, and a wide model range from L035 to L276, there is a model to suit every application.

👉 Need an L Type coupling for your application? Contact us with your model size and bore requirements.

Inquiry now:

www.apexcoupling.com

ella@apexcoupling.com