Spacer sleeves and spacer discs – Materials and shapes

Spacer sleeves and spacer discs are important elements for joining and design engineering solutions. They perform several tasks: They are spacers, distribute incident forces, secure components and are needed for precision adjustments. In addition to classic metal washers, this article also discusses other special shapes and configuration options, such as round plates.

Spacer Sleeves and Spacer Discs

Spacer sleeves and spacer discs, also called spacer bushings, primarily act as spacers in relation to a specified position. Spacer sleeves and spacer discs are usually fastened with a screw inserted through the inner diameter of the sleeve or disc. They are usually not stamped, as is otherwise common for metal washers (find here more information), but are instead roll-formed and have a precise length. The length tolerance (also precision class) is up to ± 0.01 mm. Due to their high precision, some can even be used as a bearing sleeve for rolling bearings.

One application example for spacer sleeves is their use in a shaft:

Spacer sleeve in a shaft: (1) Bearing, (2) Shaft, (3) Spacer sleeve

Spacer sleeve for increased distance: (1) Spacer sleeve

A spacer sleeve or spacer disc can also be used as a spring plate, for example to act as a support or stop for a compression spring.

Application example with spring: (1) Metal disc, (2) Shaft, (3) Spring

Preload washer in a screw connection: (1) Plate, (2) Metal disc, (3) Screw – Hex socket

For more information on the different types of shaft attachment and shaft ends, please also read our article “Linear Shafts: Shaft ends and linear shaft mounting options.”

Round Plates

Round plates are round metal discs with holes that are thicker than washers or spacer discs and have a larger diameter. They are used e.g. as end washers in shaft guides for securing or clamping. For this purpose, we recommended using them in applications that require high positioning accuracy and securing. As shaft end washers, round plates also take on the task of protecting against mechanical damage and preventing the ingress of dirt or dust. Round plates are particularly suited in applications with high loads or where the surfaces of the components are particularly sensitive. They also distribute forces over a larger surface.

The Importance of Standardized Parts

Standardized parts, such as standardized discs, are standardized elements that play a large role in manufacturing and design engineering. The standardization ensures uniformly high quality and compatibility (find more information here). Standardized parts simplify the assembly and replacement of standardized parts. For example, various standards apply to spacer discs:

DIN 125 / ISO 7089: Standardized washers for general-purpose applications that are used as washers for threaded connections.
DIN 988: Shim washers with defined thickness for precise spacing requirements. They are used e.g. between retaining rings and locking washers to compensate for the play when securing components axially.
DIN 7349: Reinforced washers for screws with higher loads. They provide a larger contact area and increase resistance to high forces and torques.

Configuration options

Standardized parts are sufficient for many applications. Nevertheless, they often reach their limits when requirements are elevated: a specialized solution is needed in this case. Customized components permit solutions to specific challenges. MISUMI has different configuration options for spacer discs and spacer sleeves. Some of the most important variants and their characteristics are described below.

Material selection for spacer discs and spacer sleeves

MISUMI has non-hardened and hardened discs and sleeves. Hardness affects wear: the harder the material, the more resistant the sleeves and washers are to deformation and wear. The choice of material also has an influence: stainless steel spacer sleeves and stainless steel spacer discs are suited for corrosive environments. MISUMI can also configure spacer discs and spacer sleeves made of plastic, ceramic, rubber, felt or thermally insulating materials for special environmental conditions. The use of rubber and felt is advantageous, for example, for applications that require vibration absorption or antistatic properties.

Spacer sleeves made of different materials

Spacer sleeves with special shapes

Spacer sleeves are cylindrical components. They are used to create a certain distance between two components. Special shapes may include:

Conical/Cylindrical -Cylindrical spacer sleeves are the standard shape and are suited for most industrial applications. Conical spacer sleeves have a tapered shape.
Internal and external thread Spacer Sleeves with internal threads act like a nut to facilitate threaded connections. Additional nuts and screws can be omitted.
Special Shape Washer - Suited for shaft attachment on the shaft end.
Spacer sleeve with flange - Flanges provide a larger contact surface and can act as a stop.

At MISUMI, sleeves with collar can be configured in the shape of a flange. The height of the collar is specified with tolerances and can be used for precise distance requirements.

Configurable Shim Washers

MISUMI supplies shim washers made of steel, stainless steel, spring steel and brass. The available accuracy ranges from ± 0.11 to ± 0.003 mm, which allows components to be adjusted very accurately. Please find more information about tolerance classes according to ISO 22081 and DIN ISO 2768 in our our blog.Inside diameters are available from 2 to 130 mm and outside diameters from 3 to 160 mm. MISUMI supplies standardized shim washers in various shapes and designs, standardized shim washers according to DIN 988, and configurable shim washers. Configured shim washers can be found in the MISUMI Shop, for example using the search term #CIMA.

Metal discs by Precision Class

MISUMI allows you to configure spacer discs and spacer sleeves to your specifications. The distance between two components can be adjusted very accurately with precision-manufactured spacer sleeves. If several sleeves are required, there are also simultaneously ground spacer sleeves of the same length, at least as a set of two. This allows a flat surface to be formed, reducing play due to a height difference of less than ± 5μ.

The following figures show the difference between the standard and precision version of spacer discs and spacer sleeves from MISUMI:

Design options for a sample spacer sleeve: (1) Standard version, (2) Precision version

Design options for a sample spacer disc: (1) Standard version, (2) Precision version

You can find user-configurable metal discs in the online shop, e.g. using the search term #FWS.

Overview of Discs and Sleeves in the MISUMI Shop

MISUMI offers a wide range of metal discs and metal sleeves. The following table provides an overview of variants and configuration options:

Shape		Note	Range		Tolerance	Tolerance	Type
Disc	Metal disc	- Selectable dimension T - Dimensions selectable depending on T	Thickness T from 1 to 10 mm	Standard class	Dimension T: ±0.1 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	WSSB, WSSM, WSSS
		- Dimension T configurable (in increments of 0.5 mm) - Dimensions configurable					TWSSB, TWSSM, TWSSS
		Dimensions configurable					FWS, FWSSC, FWSSB, FWSSM, FWSSR, FWSSA, FWSSAB, FWSBB, FWSSS, FWSSSR, FWSUS
	Metal disc selectable tolerance	Dimensions configurable Tolerance of dimensions D and V selectable	Thickness T from 1 to 10 mm	Standard class	Dimension T: ±0.1 mm	Dimension V selectable: Tolerance (H): H7 Tolerance (N): 0.3 mm/0.1 mm Tolerance (X): (0.2 mm/0) Dimension D selectable: Tolerance (G): g6 Tolerance (H): h7 Tolerance (N): -0.1 mm/-0.3 Tolerance (X): 0 mm/-0.2	SWSC, SWSB, SWSM, SWSS
	Metal disc selectable tolerance		Thickness T from 1 to 10 mm	Precision class	Dimension T: ±0.01 mm		SWMC, SWMB, SWMM, SWMS
	Metal disc	- Selectable dimension T - Dimensions selectable depending on T	Thickness T from 1 to 10 mm	Precision class	Dimension T: ±0.01 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	WASB, WASM, WASS
		- Dimension T configurable (in increments of 0.5 mm) - Dimensions configurable					TWASB, TWASM, TWASS
		Dimensions configurable					FWAS, FWASC, FWASB, FWASM, FWASR, FWASA, FWASS, FWASSR, FWASU
	Metal disc hardened version	- Selectable dimension T - Dimensions selectable depending on T	Thickness T from 1 to 10 mm	Standard class	Dimension T: ±0.1 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	WSSBH, WSSMH, WSSSH
		- Dimension T configurable (in increments of 0.1 mm) - Dimensions configurable		Standard class	Dimension T: ±0.1 mm		FWSSCH, FWSSBH, FWSSMH, FWSSK, FWSSKB, FWSSKM, FWSSSH, FWSSSHR
		- Selectable dimension T - Dimensions selectable depending on T		Precision class	Dimension T: ±0.01 mm		WASBH, WASMH, WASSH
		- Dimension T configurable (in increments of 0.1 mm) - Dimensions configurable		Precision class	Dimension T: ±0.01 mm		FWASCH, FWASBH, FWASMH, FWASK, FWASKB, FWASKM, FWASSH
	Metal disc selectable tolerance	- Dimension T configurable (in increments of 0.1 mm) - Dimensions configurable	Thickness T from 1 to 10 mm	Standard class	Tolerance selectable: Tolerance (B) = dimension T: -0.1 mm/-0.3 mm Tolerance (C) = dimension T: 0.3 mm/0.1 mm Tolerance (D) = dimension T: 0/-0.2 mm Tolerance (E) = dimension T: 0.2 mm/0	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	AWSC, AWSB, AWSM, AWSS, AWSH
		- Dimension T configurable (in increments of 0.1 mm) - Dimensions configurable		Precision class	Tolerance selectable: Tolerance (SB) = dimension T: -0.01 mm/-0.03 mm Tolerance (SC) = dimension T: 0.03 mm/0.01 mm Tolerance (SD) = dimension T: 0/-0.02 mm Tolerance (SE) = dimension T: 0.02 mm/0
		- Dimension T configurable (in increments of 0.1 mm) - Dimensions configurable		High precision class	Tolerance (A) = dimension T: ±0.005 mm
	Metal disc with flange	- Dimension L configurable (in increments of 0.1 mm) - Dimensions configurable	Dimension L from 2 to 10 mm	Standard class	Dimension L: 0/-0.3 mm	Dimension T: ±0.1 mm Dimension H: 0/-0.2 mm Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	FTCSS, FTCC, FTCB, FTCM, FTCSK, FTCSKB, FTCSKM, FTCS
	Metal disc with flange		Dimension L from 2 to 10 mm	Precision class	Dimension L: ±0.01 mm		FTCMC, FTCMB, FTCMM, FTCMS
	With cylinder counterbore	- Selectable dimension T - Dimensions selectable depending on T	Thickness T from 6 to 20 mm	Standard class	Dimension T: ±0.1 mm	Dimension H: ±0.1 mm Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm Dimension P: 0.3 mm/0.1 mm	WZAB, WZAM, WZAS, WZABH, WZAMH, WZASH
		- Dimension T configurable (in increments of 0.5 mm) Dimensions selectable depending on T	Thickness T from 3 to 20 mm				TWZAB, TWZAM, TWZAS
		- Dimension T configurable (in increments of 0.5 mm) - Dimensions configurable	Thickness T from 3 to 50 mm				FWZASS, FWZAC, FWZAB, FWZAM, FWZAA, FWZAAB, FWZAS, FWZACH, FWZABH, FWZAMH, FWZASK, FWZASKB, FWZASKM, FWZASH
	With cylinder counterbore	- Dimension T configurable (in increments of 0.5 mm) Dimensions selectable depending on T	Thickness T from 3 to 20 mm	Precision class	Dimension T: ±0.01 mm	Dimension T: ±0.01 mm Dimension H: ±0.1 mm Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm Dimension P: 0.3 mm/0.1 mm	TWZSB, TWZSM, TWZSS
	With cylinder counterbore	- Dimension T configurable (in increments of 0.1 mm) - Dimensions configurable	Thickness T from 3 to 50 mm	Precision class	Dimension T: ±0.01 mm		FWZSC, FWZSB, FWZSM, FWZSS
	Threaded	- Selectable dimension T - Dimensions selectable depending on T	Thickness T from 3 to 20 mm	Standard class	Dimension T: ±0.1 mm	Dimension D: 0/-0.2 mm	WTAB, WTAM, WTAS
		- Dimension T configurable (in increments of 0.5 mm) - Dimensions selectable depending on T	Thickness T from 3 to 20 mm				TWTAB, TWTAM, TWTAS
		- Dimension T configurable (in increments of 0.5 mm) - Dimensions D between 6 and 100 mm configurable - M2 to M30 selectable	Thickness T from 3 to 50 mm				FWTAC, FWTAB, FWTAM, FWTAA, FWTAAB, FWTAS
	counterbore/recessed screw head	- Selectable dimension T - Dimensions selectable depending on T	Thickness T from 2.5 to 8 mm	Standard class	Dimension T: ±0.1 mm	Dimension E: ±0.1 Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	WSRB, WSRM, WSRS
	counterbore/recessed screw head	- Dimension T configurable (in increments of 0.5 mm) - Dimensions configurable	Thickness T from 2 to 10 mm	Standard class	Dimension T: ±0.1 mm		FWSRC, FWSRB, FWSRM, FWSRA, FWSRS
	With screw holes	- Dimension T configurable (in increments of 1 mm) - Dimensions configurable	Thickness T from 1 to 10 mm	Standard class	Dimension T: ±0.1 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	WBAC, WBAB, WBAM, WBAA, WBAS
	Shape freely selectable	- Dimension T configurable (in increments of 0.1 mm) - Dimensions configurable	Thickness T from 3 to 10 mm	Standard class	Dimension T: ±0.1 mm	Measure V: shape-dependent Dimension D: shape-dependent	KWSC, KWSB, KWSM, KWSS
Sleeve	Pipe sleeve (with weld on the inner diameter)	- Dimension L configurable (in increments of 0.5 mm) - Selectable dimensions depending on L	Dimension L from 6 to 200 mm in 0.5 mm increments	Standard class (Precision class is optionally possible for dimension L)	Dimension L: ±0.2 mm Tolerance change from ±0.2 mm to ±0.05 mm possible with (LKC)	Dimension D: Tolerance not specified Dimension d: Tolerance not specified +H10	SGP, SGPBB, STPG, STPGB, STPGH, STPGHB
	Spacer sleeve (rolled steel)	- Dimension L selectable - Selectable dimensions depending on L	Dimension L from 3 to 30 mm	-	Dimension L: ±0.05 mm (for 3, 4, 5, 8, 10 mm) Dimension L :±0.1 mm (for 12, 15, 20 mm) Dimension L: ±0.15 mm (for 30 mm)	Dimension D: Tolerance not specified Dimension d: Tolerance not specified	SMKB
	Simultaneously ground spacer sleeves (at least 2 pieces)	- Dimension L configurable (in increments of 0.1 mm) - Dimensions configurable depending on L	Dimension L from 1 to 100 mm in 0.1 mm increments	-	Dimension L: ±0.05 mm Machining in one clamping process Tolerance dimension L: ±0.05 mm per clamping process	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	DWSSB, DWSSM, DWSSS, DWSSKB, DWSSKM
	With collar/stepped	- Dimension L configurable (in increments of 0.1 mm) - Dimensions configurable depending on L	Dimension - L from 1 to 50 mm in 0.1 mm increments Dimension - T from 1 to 20 mm in 0.1 mm increments	-	Dimension L: 0/-0.1 mm Dimension T: ±0.05 mm	Dimension H: 0/-0.2 mm Measure V: H7 Dimension D: h7	DCLB, DCLM, DCLS
	With collar/stepped			-	Dimension L:+0.1 mm/0 Dimension T: ±0.05 mm	Dimension H: 0/-0.2 mm Measure V: H7 Dimension D: h7	MCLB, MCLM, MCLS
	With collar/stepped Dimension T standardized	- Dimension L configurable (in increments of 0.1 mm) - Dimensions D and V selectable depending on L	Dimension L from 10 to 100 mm in 0.1 mm increments	Standard class	Dimension L: 0/-0.3 mm Dimension T: 5 mm ±0.1 mm	Dimension H: 0/-0.2 mm Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	TCLB, TCLM, TCLA, TCLSS,FTCLS
	With collar/stepped	- Dimension L configurable (in increments of 0.1 mm) - Dimensions configurable depending on L	Dimension L from 10 to 100 mm in 0.1 mm increments	Standard class	Dimension L: 0/-0.3 mm Dimension T: ±0.1 mm	Dimension H: 0/-0.2 mm Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	FTCLC, FTCLB, FTCLM, FTCLBB, FTCLA, FTCLAB, FTCLSS, FTCLCH, FTCLBH, FTCLMH, FTCLSK, FTCLSH
	With collar/stepped		Dimension L from 10 to 100 mm in 0.1 mm increments	Precision class	Dimension L: ±0.01 mm Dimension T: ±0.01 mm	Dimension H: 0/-0.2 mm Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	FTCLMC, FTCLMB, FTCLMM, FTCMSH
	Thin-walled metal sleeve	- Dimension L configurable (in increments of 0.5 mm) - Dimension V and T selectable	Dimension L from 3 to 20 mm in 0.5 mm increments	-	Dimension L: ±0.05 mm (from 3.0 to 10.0 mm) Dimension L: ±0.1 mm (from 10.5 to 20.0 mm)	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	TASC
	Metal sleeve	- Dimension L selectable - Dimension V and D selectable depending on L	10, 12, 15, 20, 25, 30, 35 mm	Standard class	Dimension L: 0/-0.1 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	KNCLB, KNCLM, KNCLSS
	Metal sleeve	- Dimension L configurable (in increments of 0.1 mm) - Dimension V and D selectable depending on L	Dimension L from 10 to 100 mm in 0.1 mm increments	Standard class	Dimension L: 0/-0.1 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	NCLC, NCLB, NCLM, NCLA, NCLSS
	Metal sleeve		Dimension L from 10 to 100 mm in 0.1 mm increments	Precision class	Dimension L: ±0.01 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	ACSC, ABSC, AMSC, AASC, SASC
	Metal sleeve	- Dimension L configurable (in increments of 0.1 mm) - Dimension V and D selectable depending on L	Dimension L from 10 to 100 mm in 0.1 mm increments	Standard class	Dimension L: 0/-0.1 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	FNCL, FNCLC, FNCLB, FNCLM, FNCLR, FNCLBB, FNCLA, FNCLAB, FNCLSS, FNCLSSR
	Metal sleeve		Dimension L from 10 to 100 mm in 0.1 mm increments	Precision class	Dimension L: ±0.01 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	FAC, FACS, FABSC, FAMSC, FARSC, FAASC, FSASC, FSASCR
	Metal sleeve - Inside Ø/outside Ø tolerance selectable - L dimension configurable	- Dimension L configurable (in increments of 0.1 mm) - Dimension V and D configurable depending on L - Tolerance selectable for D and V	Dimension L from 10 to 100 mm in 0.1 mm increments	Standard class	Dimension L: 0/-0.1 mm	Dimension V selectable: H=H7 / N=(0.3/0.1) mm / X=(0.2-0) mm Dimension D selectable: G=g6 mm / H=h7 / N=(-0.1/-0.3) mm / X=(0/-0.2) mm	SNCC, SNCB, SNCM, SNCS
			Dimension L from 10 to 100 mm in 0.1 mm increments	Precision class	Dimension L: ±0.01 mm	Dimension V selectable: H=H7 / N=(0.3/0.1) mm / X=(0.2-0) mm Dimension D selectable: G=g6 / H=h7 / N=(-0.1/-0.3) mm/X=(0/-0.2) mm	SNMC, SNMB, SNMM, SNMS
	Metal sleeve hardened - L- dimension configurable	- Dimension L configurable (in increments of 0.1 mm) - Dimension V and D selectable depending on L	Dimension L from 10 to 100 mm in 0.1 mm increments	Standard class	Dimension L: 0/-0.1 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	NCLCH, NCLBH, NCLMH, NCLSSH
	Metal sleeve hardened - L- dimension configurable		Dimension L from 10 to 100 mm in 0.1 mm increments	Precision class	Dimension L: ±0.01 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	ASH, ASC, PASC, SASCH
	Metal sleeve hardened - L dimension configurable - V dimension configurable - D dimension configurable	- Dimension L configurable (in increments of 0.1 mm) - Dimension V and D configurable depending on L	Dimension L from 10 to 100 mm in 0.1 mm increments	Standard class	Dimension L: 0/-0.1 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	FNCLCH, FNCLBH, FNCLMH, FNCSK, FNCSKB, FNCSKM, FNCLSH
			Dimension L from 10 to 100 mm in 0.1 mm increments	Precision class	Dimension L: ±0.01 mm	Dimension V: 0.3 mm/0.1 mm Dimension D: 0/-0.2 mm	FAS, FASC, FPASC, FASK, FASKB, FASKM, FSASCH

Profile Rail Guides - Selection Tool for Linear Guides

Selecting the right profile rail guide has a lasting impact on the performance and longevity of machines and equipment. But how do you find the right system among a wide range of options? Check out our blog to see what criteria really matter, from load types and accuracy requirements to environmental and installation conditions. We will show you a structured approach to help you make informed decisions and to optimize the performance of your applications over the long term.

Basic knowledge Construction Linear Motion

9 Minutes read

Profile Rail Guides - Precision Standards of MISUMI Profile Rail Guides

What makes a linear guide profile rail guide the first choice for precise and resilient motion control? In our blog, you will learn all about the design, the different versions, dimensional tolerances and the key parameters, such as running parallelism, preload and axial play. We show how these features work together perfectly to ensure the highest precision and durability – and how you can best match these components to your needs.

Construction Linear Motion Positioning

11 Minutes read

Standard parts and their importance for industry

Standardized parts are components manufactured to a specific standard. They are an integral part of modern industry because they offer a number of benefits. This article explains what standardized parts are and explains the advantages and disadvantages they bring.

Standard parts