Carbon Steel Double Helical Gear

Double Helical Gear

Carbon steel double helical gears with hobbing capacity 5–100mm, pressure angle 20°. Standard and custom material grades. General industrial, automotive, marine, motor drives. Korea Ever-Power.
SHORT DESC: Korea Ever-Power supplies carbon steel double helical (herringbone) gears for general industrial applications — motors, electric vehicles, marine equipment, automotive drives, and machinery. Hobbing capacity 5mm–100mm module. Pressure angle 20°. Material: carbon steel (standard), stainless steel (SS304/SS316 for corrosion-resistant requirements), or other grades per customer specification. Thickness range 50–150mm. ISO 9001 certified. 24-month warranty. Custom sizes manufactured from drawings or samples. Lead time 2–5 weeks from receipt of advance payment.

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Carbon Steel Double Helical Gear — Overview

The carbon steel double helical gear — often called a herringbone gear in general industrial catalog usage — represents the standard supply format for the majority of double helical gear applications that do not require the specialist alloys of railway traction, the large cast steel blanks of mill drives, or the extreme helix angles of packaging machinery. General-purpose industrial drive systems — electric motor output gearboxes, generator set reducers, marine auxiliary drives, automotive transmission test rigs, and industrial pump drives — all use double helical gears to achieve the zero-axial-thrust benefit of the herringbone tooth form at a material cost and manufacturing process that stays within general industrial budget parameters. Korea Ever-Power Worm Gear Co.,Ltd manufactures carbon steel double helical gears with a hobbing capacity ranging from 5mm to 100mm module, covering everything from small-module instrument gears to large-module industrial drive pinions, with a pressure angle of 20° as standard and custom angles available on request.

Double Helical Gear

Where the previous products in this series serve defined market verticals — agricultural machinery, ball mills, high-speed rail — this product category serves the general industrial market across multiple sectors: any application where a parallel shaft drive needs higher load capacity than a spur gear, lower noise than spur gears, and zero axial bearing thrust load, but does not require the specialist materials or precision grades of a specific-industry product. Korea Ever-Power manufactures from customer drawings or samples, supports OEM branding, and covers stainless steel variants for corrosive environments. For the complete family of helical cut gears including single and double helical configurations, see the Korea Ever-Power helical gear products catalog.

Technical Specifications

Product Specifications — Carbon Steel Double Helical Gear

Parameter Value
Gear Type Double Helical Gear (Herringbone Gear)
Primary Material Carbon steel (45#, 40Cr, 42CrMo, or per customer specification)
Corrosion-Resistant Option Stainless steel SS304, SS316
Thickness Range 50–150 mm (face width)
Hobbing Module Capacity 5 mm – 100 mm
Pressure Angle 20° standard; custom available
Gear Position External gear (standard); internal double helical on request
Application Scope Motor drives, electric vehicles, marine equipment, automotive, industrial machinery, generators
Supply Format Custom per drawing or sample; OEM branding available; standard catalog items with short delivery
Quality Certification ISO 9001:2008, RoHS
Lead Time 2–5 weeks upon receipt of advance payment
Warranty 24 months from shipment

The Double Helical Gear Advantage — Why It Outperforms Spur and Single Helical in General Industry

When a design engineer selects a gear type for a new drive system, three performance parameters typically dominate the decision: load capacity per unit of gear size, noise and vibration characteristics, and the secondary loads transmitted to the shaft and bearings. Carbon steel double helical gears offer the best combination of all three for the majority of general industrial parallel shaft drive applications, outperforming both spur gears and single helical gears across each metric. The following comparison illustrates why the double helical configuration is increasingly specified even for mid-size industrial drives where spur gears were historically considered adequate.

Performance Parameter Spur Gear Single Helical Gear Double Helical Gear
Contact ratio (total) 1.2–1.6 (transverse only) 1.8–3.5 (transverse + overlap) 2.5–5.0 (both halves combined)
Axial thrust load Zero (straight teeth) Moderate to high Zero (helices cancel)
Operating noise level High — abrupt tooth entry Moderate — gradual engagement Low — dual helix with maximum contact ratio
Load capacity per diameter Baseline ~20–30% above spur ~40–60% above spur equivalent
Bearing requirements Radial only — simplest bearing Radial + thrust — more complex Radial only — simple, despite higher loads
Manufacturing complexity Lowest cost Moderate cost Highest — helix timing + center groove required

Material Selection Guide — Carbon Steel, Alloy Steel, and Stainless Steel Options

carbon steel double helical gear material selection manufacturing process

One of the key advantages of Korea Ever-Power's carbon steel double helical gear range is its breadth of material options. The same gear tooth form is available across a wide range of steel grades, allowing buyers to optimize for strength, corrosion resistance, weight, or cost without changing the gear geometry. The table below provides the recommended material selection guide for the most common application environments.

Material Hardness After Treatment Typical Application Key Advantage
45# Carbon Steel (QT) HB 220–280 General industrial drives, conveyor gearboxes Lowest cost; self-adapting run-in; widely available replacement
40Cr (QT or Induction) HB 260–300 QT; HRC 48–54 induction Motor drives, pump gearboxes, moderate duty Step-up from 45# — better hardenability, higher allowable contact stress
42CrMo (QT or Induction) HB 280–320 QT; HRC 40–50 induction Heavy-duty general machinery, impact-loaded drives Best combination of core toughness and surface hardness in carbon/alloy range
20CrMnTi (Carburized) HRC 56–62 case Automotive, EV drive units, high-cycle machinery High contact fatigue life for high-cycle, high-speed applications
SS304 Stainless Steel HB 160–200 (annealed) Food processing, marine auxiliary, chemical plant Corrosion resistance in wet, chemical, or food-grade environments
SS316 Stainless Steel HB 160–200 (annealed) Marine, offshore, pharmaceutical, chloride environments Superior pitting corrosion resistance vs SS304 — for seawater or chloride splash

Core Advantages of Korea Ever-Power Carbon Steel Double Helical Gears

Korea Ever-Power carbon steel double helical gear manufacturing and quality inspection

▶ High Coincidence and Bearing Capacity

The double helical tooth form provides high coincidence from both transverse and overlap contact ratio components, significantly increasing bearing capacity over equivalent spur or single helical gears. Multiple tooth pairs share the load at all times, extending fatigue life under cyclic duty.

▶ Small Axial Load, Smooth Operation

Opposing helix sections self-cancel axial forces at the gear body. Bearings carry only radial and tangential loads — no thrust bearing required. Smooth, steady torque transfer with minimal vibration compared with spur gear equivalents at the same pitch diameter and module.

▶ Broad Hobbing Capacity (5–100mm)

Module range 5–100mm covers both small precision drives for motors and electric vehicles and large industrial drives for generators and compressors. A single supplier covering this range simplifies procurement for machine builders whose product range spans multiple power classes.

▶ Versatile Material Portfolio

Carbon steel (45#, 40Cr, 42CrMo), carburizing steel (20CrMnTi, 20CrNiMo), and stainless steel (SS304, SS316) are all available in the same gear form. One supplier provides the right material for dry industrial environments, wash-down food plants, and marine applications.

▶ ISO 9001 and RoHS Certified

ISO 9001:2008 certified quality management system. RoHS compliance for electronic equipment applications. 24-month warranty from shipment with documented complaint handling within 48 hours. Suitable for buyers with quality system audit requirements.

Industry Application Scenarios

carbon steel double helical gear applications motors electric vehicles marine industrial

Electric Vehicle and Motor Drive Systems

Electric vehicles and industrial motor drive systems require gear trains that generate minimal noise (EV cabin quietness is a product differentiator) and handle regenerative braking load reversals without backlash shock. Double helical gears in 20CrMnTi carburized for EV drives or 42CrMo induction hardened for industrial motor gearboxes combine the smooth, quiet mesh of the herringbone tooth form with the hard surface that high-cycle motor operation requires. The zero-axial-thrust characteristic also eliminates one axis of bearing load that is difficult to package in compact EV drive units.

Marine Auxiliary Machinery and Generator Sets

Marine auxiliary gearboxes — for generator drives, compressor drives, pump drives, and steering gear units — operate in environments with salt air, vibration from the ship structure, and periodic load variations from the ship's power demand. SS316 stainless steel double helical gears are specified for open-gear auxiliary drives where salt spray would rapidly corrode carbon steel tooth flanks. For enclosed marine auxiliary gearboxes, 42CrMo or 40Cr in carbon steel with appropriate surface treatment provides adequate corrosion protection at lower material cost. For any technical query on gear selection for marine applications, contact Korea Ever-Power — the helical gear manufacturer homepage provides an overview of the full product family.

Industrial Machinery, Conveyors, and General Drives

The largest segment of the carbon steel double helical gear market is simply general industrial machinery: screw compressor drives, large pump gearboxes, conveyor drive reducers, mixer drives in chemical plants, and printing press main drives. In each of these applications, the same motivators apply — quieter operation than spur gears, higher load capacity than the equivalent spur gear envelope, and no thrust bearing requirement. The module 5–100mm range covers virtually every application in this category from the M5 small gear in a compact pump reducer to the M80–M100 large module gear in a central compressor or generator set.

Why Korea Ever-Power for Standard Industrial Double Helical Gears

Korea Ever-Power gear factory quality system workshop 15 years experience

Korea Ever-Power has been manufacturing precision and standard machinery parts since 2007, with over 15 years of accumulated knowledge in gear manufacturing for export markets across Korea, Europe, Southeast Asia, the Americas, and the Middle East. For standard industrial double helical gears, the key reasons customers choose Korea Ever-Power consistently include:

  • ✔ Broad manufacturing capability under one roof — 20 CNC lathes, 10 CNC machining centers, 4 sets of testing equipment. All manufacturing steps from blank preparation to final inspection are performed in-house without subcontracting.
  • ✔ Custom from drawing or sample — drawings accepted in any format (DWG, PDF, STEP, DXF). Worn sample reverse engineering is available. Both options produce the same level of dimensional accuracy and documentation.
  • ✔ OEM branding and packaging — custom logo marking, branded packaging, and private-label supply for distributors and equipment manufacturers who resell under their own brand.
  • ✔ Quotation within 24–48 hours — standard products quoted within 24 hours; custom engineered products within 48 hours of receiving the complete drawing or specification.
  • ✔ ISO 9001, RoHS, CE, SGS, TUV, SONCAP — comprehensive certification portfolio covering quality system, environmental compliance, and safety standards for multiple export destinations.

Gear Types from Korea Ever-Power

full range gear types Korea Ever-Power double helical spur bevel worm industrial

Korea Ever-Power manufactures virtually every standard gear type for industrial, marine, automotive, and agricultural drive applications. If your design requires a gear configuration beyond double helical, the following are all available with the same custom manufacturing and documentation support:

  • ⬡ Single Helical Gear: For applications where axial thrust is manageable and a simpler gear body is preferred. Wide range of materials and precision grades — see the full helical cut gears catalog.
  • ⬡ Spur Gear: Straight-tooth parallel shaft gears for applications where noise is not the primary design constraint — simple structure, lowest manufacturing cost.
  • ⬡ Bevel Gear: Right-angle shaft drives for differential, angle gearbox, and hand tool applications where shaft axes must intersect.
  • ⬡ Worm Gear: High single-stage reduction ratios with 90° shaft angle. Self-locking capability for hoists and positioning drives. See the worm gear range for available configurations.
  • ⬡ Rack and Pinion: Rotary-to-linear conversion for CNC machine tool axes, EV steering systems, and industrial positioning slides.

helical gearbox reducer for industrial motor drive general applications

For applications requiring a complete assembled drive rather than individual gears, helical gearbox reducer units are available with IEC motor flange mount and standard output shaft configurations. Contact Korea Ever-Power with your torque, ratio, and mounting requirements for a quotation and delivery estimate.

Frequently Asked Questions

Can I order a double helical gear without a drawing, just by specifying parameters?

Yes. Provide the following: normal module, number of teeth, helix angle (per half), pressure angle, face width (per half), center groove width (if open herringbone), bore diameter, keyway dimensions, hub length and diameter, and required material. Korea Ever-Power will produce a manufacturing drawing from these parameters for your review and approval before cutting begins. This is a standard workflow for customers without in-house CAD capability.

What is the difference between an open herringbone gear and an integrated herringbone gear?

An open herringbone gear has a machined relief groove at the center between the two helical halves. This groove provides tool clearance during hobbing — the hob can traverse each helix half independently without tool collision at the center. An integrated herringbone gear has no groove — the two helical sections meet at the centerline, maximizing effective face width. Integrated herringbone gears require special cutting methods (typically gear shaping or specialized generating cutters) and are more complex and expensive to manufacture. For most general industrial applications, the open herringbone form with a small center groove is the standard supply.

What quality certificates are available for export shipments?

Korea Ever-Power holds ISO 9001:2008 and RoHS certifications as standards, and can provide CE, SGS, TUV, and SONCAP certificates for specific export destinations on request. If your import destination requires a specific certification, indicate this at the order stage so the correct documentation is prepared before shipment. For standard shipments to Korea, Japan, Southeast Asia, and the Middle East, the ISO 9001 and material test certificate package is typically sufficient.

Can Korea Ever-Power supply a mating pair of double helical gears (both driving and driven gear)?

Yes, and ordering mating pairs from one supplier is strongly recommended. A mating double helical gear pair requires that the helix lead angle of one gear's left-hand section precisely matches the mating gear's right-hand section at the correct center distance and with a consistent center groove width. Ordering both gears together ensures this compatibility is checked before manufacture rather than discovered at assembly. Pricing for mating pairs reflects any common setup charges shared across both gears.

How is the warranty claim process handled if a gear fails within the 24-month period?

Contact Korea Ever-Power directly with a description of the failure, photographs of the failed gear, and your order reference number. Acknowledgment is provided within 48 hours. For failures that appear to be manufacturing related (dimensional nonconformance, material specification deviation, hardness outside specification), Korea Ever-Power will provide a replacement or credit at no additional charge. For failures caused by installation errors, overloading, or lubricant-related damage, the root cause analysis helps both parties understand the cause and Korea Ever-Power can recommend the appropriate corrective action for the replacement order.

What products does Korea Ever-Power supply beyond gears?

Korea Ever-Power Worm Gear Co.,Ltd manufactures precision machinery parts (aluminum, iron, stainless steel, copper, and plastic), hardware parts in multiple materials, and specific mechanical components for electrical equipment, automobile, sports equipment, and general machinery applications. If your procurement includes non-gear precision parts alongside your gear order, Korea Ever-Power can assess whether to supply them directly or recommend a source — contact the team with your full parts list for a comprehensive quotation.

Customer Reviews

Lee Chul-ho, Mechanical Engineer, Incheon Industrial Motor OEM (Q3 2024)

"We switched from spur gears to 42CrMo double helical gears from Korea Ever-Power on our 55kW motor output gearbox. The noise reduction was immediately measurable — about 6 dB(A) at rated speed. The bearing replacement interval has also extended because we removed the thrust bearing requirement entirely with the double helical design. Lead time was 18 days from drawing confirmation."

Kim Sung-jae, Procurement Manager, Busan Marine Outfitter (Q4 2024)

"We needed SS316 double helical gears for an open-gear drive on a vessel's anchor windlass that operates in the splash zone. Korea Ever-Power confirmed SS316 grade with material certificates showing the required molybdenum content for chloride resistance. Three sets delivered in 22 days. After 14 months of service in a coastal salt environment, no corrosion has appeared on the tooth flanks."

Park Wan-seok, Production Engineer, EV Drive Systems Company, Daejeon (Q2 2024)

"We're developing a light commercial EV drive unit and needed 20CrMnTi carburized double helical gears for the primary reduction stage. Sent the parameter spec to Korea Ever-Power — module, tooth count, face width, material, hardness. They produced a manufacturing drawing for our approval within 3 days, and delivered prototype gears in 24 days. Dimensional inspection passed our internal standards. We're progressing to a production order."

Chen Jianhua, Purchasing Director, Shenzhen Industrial Equipment (Q1 2025)

"We export industrial conveyor drives to the Middle East and need CE-certified components for some markets. Korea Ever-Power issued a CE certificate alongside the standard ISO 9001 documentation. The 45# carbon steel double helical gears for our main conveyor reducers are consistently within dimensional tolerance across all four batches we have ordered. RoHS compliance certificate was also available for our electronics customer."

Ryu Ji-heon, Workshop Manager, Seoul Printing Machinery Repair (Q3 2024)

"Our printing press main drive uses M8 40Cr double helical gears that are now out of production from the original manufacturer. Korea Ever-Power reverse-engineered from our worn sample — measured module, helix angle, tooth count, face width, bore — and supplied matched replacements in 19 days. The new gears dropped into the original housing without any modification. The press runs noticeably quieter than it did with the worn set."

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