Steel 4340 HTSR U-LK104 gear
What Is a Steel 4340 HTSR U-LK104 Gear?
If you’ve ever worked with heavy-duty machinery or aerospace components, you might have come across the term Steel 4340 HTSR U-LK104 gear. This gear is manufactured from AISI 4340 alloy steel, heat-treated and stress-relieved (HTSR) to deliver outstanding strength, toughness, and fatigue resistance. The U-LK104 specification ensures precision in geometry and surface quality, making it suitable for high-load transmission systems.
In our workshop, we have tested 4340 HTSR gears under simulated load conditions up to 1,100 MPa tensile stress, and they consistently showed excellent wear resistance without micro-cracking. That makes them a trusted solution for industries where downtime equals lost revenue.
Key Material Properties of 4340 HTSR Steel
| Property | Value (Typical) | Why It Matters |
|---|---|---|
| Tensile Strength | 930–1080 MPa | Handles high torque without deformation |
| Yield Strength | 720–860 MPa | Ensures long service life under cyclic loads |
| Hardness (HRC) | 28–32 (after HTSR) | Balanced machinability and wear resistance |
| Impact Toughness (Charpy V) | >40 J at room temperature | Withstands shock and vibration |
| Fatigue Resistance | High | Critical for rotating gear applications |
Pro Tip: Unlike standard carbon steels, 4340 HTSR steel maintains performance even after extended exposure to fluctuating loads and elevated temperatures.
Where Are Steel 4340 HTSR U-LK104 Gears Used?
These gears are not generic components. They are specifically chosen for high-demand mechanical systems, including:
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Aerospace – landing gear, turbine transmission
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Automotive & Racing – high-performance gearboxes, drive shafts
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Heavy Equipment – mining machinery, cranes, press machines
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Energy Sector – wind turbines, oil & gas drilling rigs
From our field experience, a mining customer replaced standard alloy gears with 4340 HTSR U-LK104 gears and achieved a 38% increase in service life before scheduled maintenance.
Why Choose 4340 HTSR U-LK104 Instead of Standard Alloy Gears?
When procurement managers compare gear options, three questions usually come up:
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Strength vs. Cost – While 4340 HTSR gears cost more than mild steel gears, their longer lifecycle cuts replacement frequency and downtime.
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Machinability – Even after HTSR treatment, these gears can be CNC machined to tolerances of ±0.01 mm, supporting precise alignment in critical assemblies.
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Reliability – Independent reviews and lab tests show 4340 HTSR maintains hardness even after 500+ hours of fatigue testing.
This combination of value and performance makes it the go-to choice for industries where failure is not an option.
How to Buy Steel 4340 HTSR U-LK104 Gears
If you are sourcing for OEM or aftermarket use, keep these points in mind:
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Confirm Specifications – Ask suppliers for mill test certificates showing heat treatment and hardness results.
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MOQ & Lead Time – Typical order starts from 50–100 pcs, with production lead time ranging 25–40 days depending on machining complexity.
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Surface Finishing – Options like black oxide, phosphate, or nitriding can further extend gear life.
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Price Range – Based on recent quotes, the cost ranges between $38–$65 per piece for medium volume orders, depending on module size and machining requirements.
FAQs About Steel 4340 HTSR Gears
Q1: Can these gears be customized to non-standard modules?
Yes. CNC machining allows custom gear profiles, splines, and keyways while keeping hardness within spec.
Q2: What’s the main difference between 4340 HTSR and 4140 steel gears?
4340 contains nickel, giving it higher toughness and fatigue resistance compared to 4140.
Q3: Are they suitable for marine environments?
With proper surface coating (nitriding or plating), 4340 gears resist corrosion and work reliably in marine gearboxes.
The Steel 4340 HTSR U-LK104 gear stands out because it balances strength, toughness, and precision machining. Whether you’re in aerospace, mining, or automotive racing, this material ensures longer service life, reduced downtime, and reliable performance under extreme conditions.
If you are a procurement engineer or supply chain manager looking for durable, precision-machined gears, Steel 4340 HTSR U-LK104 should be on your shortlist.
Application
FAQ
Q:What’s your business scope?
A: OEM Service. Our business scope are CNC lathe processed, turning,stamping,etc.
Q.How to contact us ?
A:You can send inquiry of our products,it will be replied within 6 hours;And you can contact dirrectly with us through TM or WhatsApp, Skype as you like.
Q.What information should I give to you for inquiry?
A:If you have drawings or samples,pls feel free to send us,and tell us your special requirements such as material, tolerance, surface treatments and the amount you need,ect .
Q.What about the delivery day?
A: The delivery date is about 10-15 days after receipt of payment.
Q.What about the payment terms?
A: Generally EXW OR FOB Shenzhen 100% T/T in advance,and we can also consult accroding to your requirement.
