Double Pitch Sprockets Asian Standard

Korea Ever-Power Asian standard double pitch sprockets cover the JIS B1801 double pitch range — chain numbers NK2040 through NK2120, with each number representing double the pitch of the equivalent standard chain (NK2040 = double pitch of 40B = 25.4 mm pitch). As in the American double pitch system, the Asian double pitch sprocket exists to provide a larger pitch circle diameter for a given tooth count at lower chain and sprocket cost for slow-speed, light-load conveyors.

التصنيف: عجلات مسننة

استفسر الآن

الوصف
معلومات إضافية

NK2040 – NK2120

Chain Series

SB & RB

Standard & Large Roller

Solid & Weld

Hub Type

JIS B1801

Asian Standard

Asian Standard Double Pitch Sprockets – Product Overview

A key distinction from the American double pitch range: Asian double pitch chain is produced in two roller types — SB (Standard Bore / Standard Roller) where every link has a roller of the standard JIS diameter, and RB (Roller Bore / Large Roller) where every link has a larger carrier roller machined to a larger diameter for improved load distribution on the chain guide and sprocket. SB and RB chains are NOT interchangeable — the tooth seating curve and sprocket tooth width differ between the two roller types. Always confirm which roller type your chain uses before ordering a replacement sprocket.

The hub is available in two forms: Solid hub — a conventional hub with a bore, machined from a single piece; and Weld hub — a fabricated assembly where the tooth ring is welded onto a separate hub, used for very large diameter sprockets where a solid casting would be uneconomical. Solid hubs are standard for most sizes; weld hub is specified for larger tooth counts where the tip diameter exceeds the economical casting size.

Korea Ever-Power Asian standard double pitch sprockets NK2040 NK2060 NK2080 JIS B1801

🔍 SB vs RB — How to identify your chain

Check the chain link plate markings or measure the roller diameter:

Chain	SB Roller Ø	RB Roller Ø
NK2040	7.92 ملم	15.88 mm
NK2060	11.91 mm	22.23 mm
NK2080	15.88 mm	28.58 mm

⚠️ RB roller is always approximately 2× the SB roller diameter — if in doubt, measure and compare to this table before ordering sprocket.

Double Pitch Sprocket Specifications

NK2040 | Pitch 25.40 mm | SB Roller 7.92 mm / RB Roller 15.88 mm

Z	Do (mm)	Dp (mm)	BD stock (mm)	BD max (mm)	BL (mm)	يكتب
7	65	57.54	16	*40	25	SB/RB Solid
10	93	82.20	16	63	25	SB/RB Solid
14	127	114.45	16	63	25	SB/RB Solid
16	143	130.20	20	68	28	SB/RB Solid

NK2080 | Pitch 50.80 mm | SB Roller 15.88 mm / RB Roller 28.58 mm

Z	Do (mm)	Dp (mm)	BD stock (mm)	BD max (mm)	BL (mm)	يكتب
6½	118	109.31	16	70	40	SB Solid
7	136	117.08	20	76	40	RB Solid
8½	151	140.63	20	93	40	SB Solid / Weld
11½	200	188.29	26	107	45	SB Solid / Weld
12½	216	204.27	26	107	45	SB Solid / Weld

NK2060 and NK2100 available — contact us. Half-tooth counts (6½, 8½ etc.) indicate that the chain engages alternate teeth — normal for RB type. Specify: chain number (e.g. NK2080), tooth count, type (SB or RB), hub (Solid or Weld) and bore diameter mm.

Features & Applications

Half-Tooth Count for RB Type

RB double pitch sprockets are listed with half-tooth counts (6½, 7½, 8½) because only alternate teeth engage the large rollers of the RB chain — the remaining teeth pass through the plain-pin spaces between rollers. A "6½ tooth" RB sprocket engages 6 rollers and 7 plain pins per revolution. This gives smooth motion with fewer engagement impacts than a same-size SB sprocket where all teeth engage rollers.

Weld Hub for Large Diameters

For NK2080 and NK2100 at large tooth counts (Do above 150 mm), the weld hub construction is used where the tooth ring is plasma-cut from steel plate and welded onto a separate machined hub. This reduces both material waste and machining time compared to a solid casting of the same size. The weld hub is dimensionally equivalent to the solid hub and uses the same bore and keyway specification.

Conveyor Economy Application

Double pitch sprockets and chain are the standard specification for slow Japanese and Korean-manufactured slat conveyors, overhead trolley conveyors and pallet accumulation systems. NK2040 at Z=10 provides a 250 mm pitch circle diameter — equivalent to a standard NK40B Z=20 sprocket — at significantly lower chain cost per metre. For conveyor speeds below 0.5 m/s and light loads below 200 kg total chain pull, NK2040 chain and sprockets are the most cost-effective drive solution. Match with JIS double pitch conveyor chain.

JIS B1801 Tooth Profile

Both SB and RB tooth profiles conform to JIS B1801 for the respective roller diameter. The SB sprocket tooth is machined for the standard roller diameter; the RB sprocket tooth is machined for the larger carrier roller. The two profiles are not interchangeable — always confirm the chain roller type (SB or RB) from the chain link plate marking before ordering a replacement sprocket.

سلسلة متناسقة ومنتجات ذات صلة

JIS Asian standard double pitch conveyor chain NK2040 NK2060 NK2080

Matching Asian Double Pitch Chain

Match NK2040/2060/2080 sprockets with JIS B1801 double pitch chain in SB or RB type. K-attachment variants available for slat and overhead trolley conveyors. Never run standard pitch 40B/60B/80B chain on double pitch sprockets.

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