Double Sprockets for Two Single Chains Asian Standard

Korea Ever-Power Asian standard double sprockets for two single chains (SD series) are designed to drive two parallel single-strand JIS B1801 chains simultaneously from one shaft. The hub carries two JIS tooth rows machined to the correct profile for the chain size, separated by the standard centre-to-centre spacing (BL dimension) for that chain size. Both chain rows are independent — separately tensioned, separately replaceable.

カテゴリー:

40SD – 80SD

Available Types

Z=12 – 21

歯の本数範囲

C45 Hardened

Induction Teeth

JIS B1801

Asian Standard

Double Sprockets for Two Single Chains – Asian Standard

The SD designation follows the pattern: 40SD = double simplex sprocket for 40B chain; 60SD = double simplex for 60B chain, and so on. The range covers 40SD, 50SD, 60SD and 80SD, with tooth counts from Z=12 to Z=21. Bore is stock bore — the hub is machined to your required shaft diameter and JIS B1301 keyway on order, up to the maximum bore listed for each tooth count. Material is C45 with induction-hardened teeth.

Applications include wide-chain Japanese and Korean agricultural machinery (grain elevators, threshers, combine harvesters), slat conveyors requiring chain spacing beyond standard duplex pitch, and industrial drives where independent chain replacement without taking down the other strand is a maintenance priority. For the equivalent American (ANSI) version see our American double simplex sprockets. Browse the フルスプロケットカテゴリ.

Korea Ever-Power Asian standard double simplex sprockets 40SD 60SD JIS B1801

📏 SD vs Duplex — chain spacing comparison

The SD (double simplex) hub allows any chain spacing up to BL dimension. Asian duplex chain fixes the spacing at the duplex inner width. For conveyor slat bars that fall between the standard duplex spacing options, SD is the only option:

タイプ 40B 60B 80B
SD BL max 35 mm 50 mm 60 mm
Duplex fixed 14.38 mm 22.78 mm 29.29 mm

For slat bars wider than the duplex inner width, SD sprockets are the only solution.

Key: Z = teeth  |  Do = tip diameter (mm)  |  Dp = pitch circle diameter (mm)  |  BD stock = pilot bore (mm)  |  BD max = max bore (mm)  |  BL = chain strand centre spacing (mm)  |  C45 hardened teeth throughout

SD Sprocket Specifications — 40SD & 60SD

40SD  |  Pitch 12.70 mm  |  Roller Ø 7.95 mm  |  BL = 35 mm

Double Sprockets for Two Single Chains -diemnsion2

Z Do (mm) Dp (mm) BD stock (mm) BD max (mm) BL (mm)
12 55 49.07 10 34 35
14 63 57.07 13 42 35
16 74 65.10 13 50 35
17 76 69.12 13 54 35
19 84 77.16 13 63 35
21 92 85.21 14 71 35

60SD  |  Pitch 19.05 mm  |  Roller Ø 11.91 mm  |  BL = 50 mm

Z Do (mm) Dp (mm) BD stock (mm) BD max (mm) BL (mm)
12 83 73.60 14 51 50
14 95 85.61 16 64 50
16 107 97.65 16 76 50
17 113 103.67 16 82 50
19 126 115.74 16 94 50
21 138 127.82 16 107 50

50SD (BL=40 mm) and 80SD (BL=60 mm) also available — contact us. Bore machined to any metric shaft size up to BD max, keyway to JIS B1301. Specify: type (40SD/50SD/60SD/80SD), tooth count and bore diameter mm.

Technical Features & Applications

Double Sprockets for Two Single Chains2

Japanese Grain Handling Equipment

40SD and 60SD sprockets are the standard specification for wide-belt bucket elevator head shafts in Japanese rice mills, grain silos and feed processing plants. The two independent chain strands allow the elevator belt width to be set at any dimension within the BL range, and allow one strand to be replaced without fully dismantling the elevator. Widely exported to Southeast Asia, Australia and South Korea in Japanese agricultural plant.

Korean Agricultural Machinery OEM

Korean combine harvesters and threshers use 40SD and 60SD sprockets for the threshing drum drive and straw conveyor shafts. The JIS B1801 chain standard is used throughout Korean agricultural OEM machinery. Korea Ever-Power 40SD and 60SD sprockets with bore machined to the OEM shaft diameter are the correct replacement for all Korean agricultural equipment chain drives.

Single-Chucking Manufacture

Both tooth rows, the bore and the hub are machined in one CNC turning centre setup. This is the critical quality requirement for a double simplex sprocket — the two tooth rows must be perfectly co-axial for equal load sharing between the two chains. A sprocket manufactured in two separate chucking operations will have inter-row runout that causes one chain to carry a disproportionate share of the load.

Hardened JIS B1801 Teeth

Both tooth rows are induction-hardened to 52–58 HRC. The tooth profile is machined to JIS B1801 before hardening; after hardening, tooth profile and bore dimensions are confirmed by dimensional inspection. Pair with JIS B1801 single-strand roller chain (two rolls, same chain size as the SD designation — 40B for 40SD, 60B for 60SD).

マッチングチェーンおよび関連製品

JIS B1801 Asian standard roller chain 40B 60B for SD double simplex sprockets

Two Rolls of JIS Asian Standard Chain

Order two separate rolls of JIS B1801 single-strand roller chain in the matching size: 40B for 40SD, 60B for 60SD, 80B for 80SD. Both chains must be the same grade and worn to the same elongation for equal load sharing.

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Request a Quote — Asian Double Simplex Sprockets

Specify type (40SD/50SD/60SD/80SD), tooth count, bore diameter in mm and required chain spacing if different from standard BL. Response within one working day.

追加情報

エディタ

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