{"id":2037,"date":"2026-04-10T08:21:02","date_gmt":"2026-04-10T08:21:02","guid":{"rendered":"https:\/\/helicalcutgears.top\/?post_type=product&p=2037"},"modified":"2026-04-10T08:21:02","modified_gmt":"2026-04-10T08:21:02","slug":"soft-tooth-flank-helical-gear-din-class-6-for-rolling-mill-auxiliary-drives","status":"publish","type":"product","link":"https:\/\/helicalcutgears.top\/bs\/product\/soft-tooth-flank-helical-gear-din-class-6-for-rolling-mill-auxiliary-drives\/","title":{"rendered":"Mekani bo\u010dni spiralni zup\u010danik \u2014 DIN klasa 6 za pomo\u0107ne pogone valjaonica"},"content":{"rendered":"
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Soft Tooth Flank Helical Gear for Metallurgy Machinery \u2014 Overview<\/h2>\n

A soft tooth flank helical gear<\/strong> is a gear whose tooth flanks are left in the normalized or quenched-and-tempered condition after hobbing and grinding, rather than being case-hardened to a high surface hardness. In this product, the material is 45# carbon steel quenched and tempered to HB 220\u2013280 \u2014 a moderate hardness range that gives a workable balance of bending strength, surface wear resistance, and machinability. Unlike carburized spiralni zup\u010danici<\/strong> that achieve HRC 58\u201362 on the tooth surface, soft tooth flank gears are deliberately kept at a hardness where the tooth flanks can slightly conform under load during an initial run-in period, self-correcting minor tooth lead and profile errors that arise from assembly misalignment or gearbox housing tolerances. This run-in characteristic makes soft tooth flank gears particularly suited to large-scale metallurgy machinery auxiliary drives where perfect shaft alignment cannot always be guaranteed over the full gear body width.<\/p>\n

\"Spiralni<\/p>\n

The reference specification for this product is Mn=3, Z=128, helix angle \u03b2=11.5\u00b0, pressure angle 20\u00b0, left-handed, giving a pitch diameter of 384mm. The large tooth count and moderate module produce a gear with a high contact ratio and inherently smooth torque transmission, suitable for the long continuous-duty cycles characteristic of metallurgical rolling mill auxiliary drives, ore conveyor gearboxes, and slab transport line drives. Korea Ever-Power Worm Gear Co.,Ltd manufactures soft tooth flank helical gears<\/strong> from forged 45# blanks, finishing to DIN 3962 class 6 accuracy with tooth grinding. Find the complete range of industrial spiralno rezani zup\u010danici<\/strong> including both soft and hard tooth flank variants across our proizvodi sa spiralnim zup\u010danicima<\/a> katalog.<\/p>\n

Tehni\u010dke specifikacije<\/h2>\n

Gear Basic Data \u2014 Reference Configuration<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n
Parametar<\/th>\nVrijednost<\/th>\n<\/tr>\n
Gear Tooth Shape<\/td>\nInvolute<\/td>\n<\/tr>\n
Materijal zup\u010danika<\/td>\n45# Carbon Steel (Quenched and Tempered, HB 220\u2013280)<\/td>\n<\/tr>\n
Gear Process<\/td>\nForging \u2192 Lathing \u2192 Hobbing \u2192 External Grinding \u2192 Keyway Milling \u2192 Tooth Grinding<\/td>\n<\/tr>\n
Ugao pritiska<\/td>\n20\u00b0<\/td>\n<\/tr>\n
Quality Level<\/td>\nDIN 3962 Klasa 6<\/td>\n<\/tr>\n
Vrsta zup\u010danika<\/td>\nMn=3, Z=128, \u03b2=11.5\u00b0, \u03b1=20\u00b0, Left-Handed<\/td>\n<\/tr>\n
Calculated Pitch Diameter<\/td>\n384 mm (Mn \u00d7 Z)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Manufacturing Capabilities \u2014 Internal Gears and Internal Splines<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n
<\/th>\nMILLING<\/th>\nSHAPING<\/th>\nTOOTH GRINDING<\/th>\n<\/tr>\n
Maximum O.D.<\/td>\n2500 mm<\/td>\n2500 mm<\/td>\n2500 mm<\/td>\n<\/tr>\n
Minimum I.D.<\/td>\n650 mm<\/td>\n50 mm<\/td>\n100 mm<\/td>\n<\/tr>\n
Maximum Face Width<\/td>\n500 mm<\/td>\n500 mm<\/td>\n500 mm<\/td>\n<\/tr>\n
Maximum Module<\/td>\n26 mm<\/td>\n26 mm<\/td>\n45 mm<\/td>\n<\/tr>\n
AGMA \/ DIN Level<\/td>\nDIN klasa 8<\/td>\nDIN klasa 8<\/td>\nDIN klasa 4<\/td>\n<\/tr>\n
Tooth Surface Finishing<\/td>\nRa 3.2<\/td>\nRa 3.2<\/td>\nRa 0,6<\/td>\n<\/tr>\n
Maximum Helix Angle<\/td>\n\u00b122,5\u00b0<\/td>\n\u00b122,5\u00b0<\/td>\n\u00b145\u00b0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Manufacturing Capabilities \u2014 External Gears and External Splines<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n
<\/th>\nHOBBING<\/th>\nMILLING<\/th>\nTOOTH GRINDING<\/th>\n<\/tr>\n
Maximum O.D.<\/td>\n1250 mm<\/td>\n2500 mm<\/td>\n2500 mm<\/td>\n<\/tr>\n
Minimum O.D.<\/td>\n20 mm<\/td>\n200 mm<\/td>\n20 mm<\/td>\n<\/tr>\n
Maximum Face Width<\/td>\n500 mm<\/td>\n500 mm<\/td>\n1480 mm<\/td>\n<\/tr>\n
Maximum Module<\/td>\n26 mm<\/td>\n26 mm<\/td>\n45 mm<\/td>\n<\/tr>\n
AGMA \/ DIN Level<\/td>\nDIN klasa 8<\/td>\nDIN klasa 8<\/td>\nDIN klasa 4<\/td>\n<\/tr>\n
Tooth Surface Finishing<\/td>\nRa 3.2<\/td>\nRa 3.2<\/td>\nRa 0,6<\/td>\n<\/tr>\n
Maximum Helix Angle<\/td>\n\u00b145\u00b0<\/td>\n\u00b145\u00b0<\/td>\n\u00b145\u00b0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Soft Tooth Flank vs Hard Tooth Flank \u2014 Which Is Right for Your Drive?<\/h2>\n

\"soft<\/p>\n

The choice between a soft tooth flank helical gear<\/strong> and a hard tooth flank (carburized or induction-hardened) gear is one of the most consequential decisions in metallurgical drive design. Each approach has a distinct performance profile, and neither is universally superior. The following comparison addresses the parameters that matter most in metallurgy machinery gearbox specifications.<\/p>\n

\n\n\n\n\n\n\n\n\n\n
Parametar<\/th>\nSoft Tooth Flank (45# QT, HB 220\u2013280)<\/th>\nHard Tooth Flank (Carburized, HRC 58\u201362)<\/th>\n<\/tr>\n
Tvrdo\u0107a povr\u0161ine<\/td>\nHB 220\u2013280 (uniform through cross-section)<\/td>\nHRC 58\u201362 surface; tough core beneath<\/td>\n<\/tr>\n
Contact fatigue strength<\/td>\nModerate \u2014 limits allowable contact stress<\/td>\nHigh \u2014 carburized case raises pitting resistance significantly<\/td>\n<\/tr>\n
Run-in behavior<\/td>\nFavorable \u2014 tooth flanks conform slightly to correct minor misalignment<\/td>\nMinimal run-in \u2014 hard surface requires precise alignment from installation<\/td>\n<\/tr>\n
Sensitivity to misalignment<\/td>\nLow \u2014 soft flanks tolerate small shaft alignment errors<\/td>\nHigh \u2014 misalignment creates edge loading on brittle hard case<\/td>\n<\/tr>\n
Tro\u0161kovi proizvodnje<\/td>\nLower \u2014 no carburizing furnace cycle required<\/td>\nHigher \u2014 carburizing adds processing time and cost<\/td>\n<\/tr>\n
Suitable applications<\/td>\nMetallurgy auxiliary drives, conveyor gearboxes, moderate continuous duty<\/td>\nMining, turbines, rolling mill main drives, high-speed high-shock applications<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

45# Steel Quench-and-Temper Process for Metallurgy Gears<\/h2>\n

\"45<\/p>\n

45# carbon steel is the most widely used material for soft tooth flank helical gears<\/strong> in metallurgy applications. It contains 0.42\u20130.50% carbon, 0.50\u20130.80% manganese, and limited alloying additions \u2014 a composition that responds predictably to quench-and-temper heat treatment and machines cleanly in the HB 220\u2013280 tempered range. The complete processing sequence for this gear reflects established best practice for large industrial gears:<\/p>\n

\"Mekani<\/p>\n

    \n
  1. Forging:<\/strong> The blank is press-forged from normalized 45# billet, aligning the grain flow with the gear’s principal stress directions. Forging improves fatigue resistance over cast stock for large-diameter gear blanks and eliminates internal porosity from the solidification process.<\/li>\n
  2. Quench and temper:<\/strong> The rough-turned blank is austenitized at approximately 840\u00b0C, water- or oil-quenched to form martensite, then tempered at 550\u2013650\u00b0C to relax internal stresses and achieve the target hardness of HB 220\u2013280. This step is performed before gear cutting, so the gear tooth form is hobbed and ground in the final heat-treated condition.<\/li>\n
  3. Hobbing:<\/strong> Tooth form is generated by hobbing using a precision worm-type cutter. At HB 220\u2013280, 45# steel machines with good surface quality in this operation and the hob tool life is acceptable \u2014 much better than attempting to hob a carburized gear, which requires the gear to be soft-cut before heat treatment and ground after.<\/li>\n
  4. External grinding and keyway milling:<\/strong> Reference surfaces (bore, hub face, keyway) are ground and milled to final dimensions after the gear tooth form is cut, ensuring datum consistency.<\/li>\n
  5. Tooth grinding:<\/strong> Final tooth grinding to DIN 3962 class 6 corrects any residual profile and lead error from the hobbing operation. For a soft tooth flank helical gear<\/strong>, tooth grinding to DIN class 6 in the as-tempered condition is significantly more straightforward than grinding after carburizing, where distortion from the heat-treatment cycle must first be corrected.<\/li>\n<\/ol>\n

    Key Advantages for Metallurgy Auxiliary Drive Applications<\/h2>\n

    \"Korea<\/p>\n

    \n
    \n

    \u25b6 Self-Adapting Run-In<\/strong><\/p>\n

    The HB 220\u2013280 surface allows micro-level conforming contact during the initial 40\u2013100 operating hours, distributing load more evenly across the face width and reducing edge stress concentrations from assembly misalignment. Hard-tooth gears require precise shimming to achieve this; soft-tooth gears achieve it naturally.<\/p>\n<\/div>\n

    \n

    \u25b6 Uniform Cross-Section Hardness<\/strong><\/p>\n

    Through-hardened QT condition means hardness is consistent from surface to core. There is no risk of hard-case spalling or delamination at the case-core interface \u2014 a failure mode that can occur in heavily loaded carburized gears when the case depth is insufficient for the actual contact stress.<\/p>\n<\/div>\n

    \n

    \u25b6 Competitive Manufacturing Cost<\/strong><\/p>\n

    Eliminating the carburizing cycle reduces both manufacturing lead time and unit cost compared with hard-tooth equivalents. For applications where tooth-surface hardness above HB 280 is not required by the service load calculation, soft tooth flank gears deliver cost-optimized performance without compromising the required service life.<\/p>\n<\/div>\n

    \n

    \u25b6 Large-Scale Capability<\/strong><\/p>\n

    External tooth grinding to OD 2500mm and module 45mm covers the full size range of metallurgy machinery large gears, including multi-strand slab caster auxiliary drives, coiler gearboxes, and run-out table drive gears that require large pitch diameters.<\/p>\n<\/div>\n

    \n

    \u25b6 Full Traceability Per Gear<\/strong><\/p>\n

    A permanent traceability code is marked on each gear body, linking it to its specific process records: heat treatment furnace number, raw material batch number, hobbing and grinding machine parameters, and dimensional inspection data. Each gear has its own traceable identity throughout its service life.<\/p>\n<\/div>\n<\/div>\n

    Metallurgy Machinery Application Scenarios<\/h2>\n

    \"soft<\/p>\n

    Rolling Mill Auxiliary and Subsidiary Drives<\/h3>\n

    A steel rolling mill contains dozens of auxiliary gearboxes beyond the main roll drives \u2014 cooling water pump drives, hydraulic system drives, scale-breaker feed drives, and manipulator rotation drives. These secondary power paths operate at lower torques than the main rolls and are less exposed to the extreme shock loads of the rolling pass. Soft tooth flank helical gears<\/strong> in 45# QT steel provide adequate contact fatigue resistance for these duty levels at a lower cost than carburized alternatives. The run-in characteristic is particularly useful in auxiliary drive gearboxes that are assembled in the mill workshop where absolute shaft alignment precision is harder to achieve than in purpose-built test rigs.<\/p>\n

    Slab Continuous Caster Drive Gears<\/h3>\n

    Continuous caster strand guide and withdrawal drive gearboxes operate in a hot, humid environment adjacent to the mold. Gearboxes in this duty run continuously at moderate constant speed and torque for extended periods between planned maintenance stops. The large tooth count of the reference gear (Z=128 on a Mn=3 blank) produces a contact ratio well above 2.0 with the mating gear, providing smooth torque transmission throughout the casting sequence. Gear replacement during planned maintenance stops is facilitated by Korea Ever-Power’s reverse engineering service \u2014 send a worn gear or drawing for a direct matched replacement.<\/p>\n

    Ore Handling and Conveyor Gearboxes<\/h3>\n

    Large-scale ore handling conveyor drives for steel plant stockyards and sintering plants use helical gearboxes to reduce motor speed to conveyor belt drive speed. The torque level is substantial but the shock loading is moderate compared with underground mining equipment. Soft tooth flank helical gears<\/strong> in forged 45# QT steel are the standard specification for these drives across the Korean and East Asian steel industry, offering a service life of 5\u201310 years between tooth flank renewal when properly lubricated with ISO VG 220\u2013320 gear oil. For complete technical support on spiralni zup\u010danik<\/strong> selection and an overview of our manufacturing capability, visit the proizvo\u0111a\u010d spiralnih zup\u010danika<\/a> Po\u010detna stranica Korea Ever-Power.<\/p>\n

    Why Korea Ever-Power for Large Industrial Helical Gears<\/h2>\n

    \"Korea<\/p>\n