Keyway on Coupling Hubs

Shaft(Bore) Diameter	Keyway Dimension						Nominal Size
Ød1/ Ød2	b(mm)				t(mm)		(b x h)
Over ~ To	Mark	No Mark	H	J	Size	Tolerance
	Size	Tolerance(E9)	Tolerance(H9)	Tolerance(Js9)
Ø6(over) ~ Ø8	2	+0.039 +0.014	+0.025 0	±0.0125	1	+0.1 0	2 x 2
Ø8 ~ Ø10	3				1.4		3 x 3
Ø10 ~ Ø12	4	+0.05 +0.02	+0.03 0	±0.015	1.8		4 x 4
Ø12 ~ Ø17	5				2.3		5 x 5
Ø17 ~ Ø22	6				2.8		6 x 6
Ø22 ~ Ø30	8	+0.061 +0.025	+0.036 0	±0.018	3.3		8 x 7
Ø30 ~ Ø38	10					+0.2 0	10 x 8
Ø38 ~ Ø44	12	+0.075 +0.032	+0.043 0	±0.0215			12 x 8
Ø44 ~ Ø50	14				3.8		14 x 9
Ø50 ~ Ø58	16				4.3		16 x 10
Ø58 ~ Ø65	18				4.4		18 x 11
Ø65 ~ Ø75	20	+0.092 +0.04	+0.052 0	±0.026	4.9		20 x 12
Ø75 ~ Ø85	22				5.4		22 x 14

• The location of keyway on a coupling hub is determined by the standard product design of Sung-il Machinery. If you need a keyway in a different location, please discuss with our Customer Support team in advance.
• The standard keyway tolerance is E9, which is the most suitable option in terms of the assembly convenience.
• If a specific keyway tolerance is required for a special case, please choose the code from the table and mention it on the PO. (Please refer to “How to order” below)
• Keyways can be applied on the following clamping methods of couplings.
_{※ exception 1: SFC series – Structurally impossible to have keyway
※ exception 2: SAD series - Due to structural interference (increased number of assembly holes),
     we ask you to check with our customer support team for availability in advance.}

※ HOW TO ORDER

• Please indicate K(b=width) next to ID(d₁)
• In general, t(depth) of a keyway is automatically determined by b(width). However if a keyway with special dimension is required, please discuss with our Customer Support team in advance. (For example, K3 will be provided with b(3mm) & t(1.4mm) unless there is a special remark.)
• Keyway Tolerance

  Mark	No Mark	H	J
  Tolerance	E9	H9	Js9

Non-standard Inner Diameter (ID) Available

Additional Tapped-holes Parts

• Sung-il Machinery provides additional tapped holes on coupling hubs upon the request.
• This additional tapped holes are usually requested when there are keyway used on a coupling.
• For this service, please contact Sung-il Customer Service team prior to firm order placement, in order to discuss accurate location of the tapped hole and the screw thread.

Parts with Alternative Material Options

• Sung-il Machinery provides alternative material options for Coupling parts.
  (FAS screws: to fasten a shaft into a coupling & ASS screws: to assemble a coupling itself)

1. 1) Stainless Steel (STS304)
2. 2) SCM435 with surface treatment -Electroless Nickel Plating

• Caution: Slip torque would become lower if the body material or surface treatment of screws are changed from the standard (SCM435, Black Oxide) version.

Case 1 : Stainless Steel

• Standard : SCM435 (Black Oxide)
• Option(1) : STS304 (Stainless Steel)

Case 2 : Surface treatment - Electroless Nickel Plating

• Standard : SCM435 (Black Oxide)
• Option(2) : SCM435
  (with surface treatment -Electroless Nickel Plating)

Side-clamp Hub Split Option

• Side-clamp Hub Split Option is available for certain sizes
• Please refer to the below table to check the coupling types which this option is available, and you can refer to “HOW TO ORDER” and “Dimensions / Performance” tables for more specific information.

※ △ symbol in the above table means that the availability is subject to differ according to each outer diameter size.