Washers - Bushing, Shoulder

Part Number	Description / PDF	Quantity
16CW375225 Richco, Inc. (Essentra Components)	CUPPED WASHER, 3/8 SCREW, .380 I	990
12SWS2529 Richco, Inc. (Essentra Components)	SHOULDER WASHER .385 ID .750 OD	2000
12SWS4000 Richco, Inc. (Essentra Components)	SHOULDER WASHER .766 ID 1.000 OD	996
FB1280A Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL,.258 IN	5800
12SWS1037 Richco, Inc. (Essentra Components)	SHOULDER WASHER .219 ID .500 O	0
10SC250012 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	24351
12SWS1029 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	10000
12SWS0418 Richco, Inc. (Essentra Components)	SHOULDER WASHER .115 ID .312 OD	1000
10SC004018 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	14994
12SWS0290 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	4780
MNI-8-16 Richco, Inc. (Essentra Components)	WASHER SHOULDER #8 NYLON	2700
MNI-8-4 Richco, Inc. (Essentra Components)	WASHER SHOULDER #8 NYLON	3490
12SWS2101 Richco, Inc. (Essentra Components)	SHOULDER WASHER .215 ID .562 OD	1000
12SWS1211 Richco, Inc. (Essentra Components)	SHOULDER WASHER .320 ID .625 OD	1000
12SWS2571 Richco, Inc. (Essentra Components)	SHOULDER WASHER .517 ID .750 OD	2000
12SWS2564 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	15000
12SWS0443 Richco, Inc. (Essentra Components)	SHOULDER WASHER .115 ID .252 OD	0
12SWS1064 Richco, Inc. (Essentra Components)	SHOULDER WASHER .190 ID .450 O	0
12SWS1076 Richco, Inc. (Essentra Components)	SHOULDER WASHER .256 ID .612 O	0
10SCM003010 Richco, Inc. (Essentra Components)	SHOULDER WASHER 3.1MM ID 6.2MM O	800

Washers - Bushing, Shoulder

1. Overview

Washers - Bushing, Shoulder are precision mechanical components combining the functions of a bushing and a washer. Featuring a stepped outer diameter design, they provide axial load distribution while maintaining precise radial alignment. These components are critical in modern machinery for reducing friction, preventing vibration-induced loosening, and protecting assembly surfaces. Their engineered geometry enables simultaneous load-bearing and spacing functionality in compact designs.

2. Major Types & Functional Classification

Type	Functional Characteristics	Application Examples
Standard Shoulder Bushing Washer	Uniform wall thickness, concentric shoulder design	General-purpose machinery, automotive linkages
Threaded Shoulder Bushing	Integrated internal threading for secure fastening	Aerospace fastening systems, vibration equipment
Split Shoulder Bushing	Segmented design for easy installation/removal	Heavy equipment maintenance, shaft repair
Flanged Shoulder Washer	Extended flange for enhanced load distribution	Structural steel connections, rail systems

3. Structural Composition

Typical construction features:

Tapered or stepped outer diameter (15 -30 transition angle)
Controlled inside diameter tolerance ( 0.025mm to 0.1mm)
Material composition: Carbon steel (SAE 1045), Stainless Steel (AISI 304/316), Bronze (SAE 841), or Polymer (Nylon 6/66)
Surface treatments: Zinc plating (8-24 m), Black Oxide, DLC coating, or PTFE impregnation
Hardness range: 200-400 HV depending on application requirements

4. Key Technical Parameters

Parameter	Significance
ID/OD Dimensional Tolerance	Ensures proper fit with shaft and housing (typically H7/g6)
Shoulder Height	Determines axial positioning accuracy ( 0.1mm standard)
Hardness Rating	Affects wear resistance and load capacity
Surface Roughness (Ra)	Impacts friction coefficient (Ra 0.8-3.2 m typical)
Corrosion Resistance	Determines service life in harsh environments

5. Application Fields

Primary industries:

Automotive: Suspension systems, transmission linkages
Aerospace: Flight control actuation systems, engine mounts
Industrial Machinery: CNC machine tool spindles, robotic joints
Railway: Bogie pivot joints, coupler systems
Renewable Energy: Wind turbine pitch bearings, solar tracker mechanisms

6. Leading Manufacturers & Products

Manufacturer	Key Product Series	Technical Features
MISUMI	WSB Series	Modular design, 12 standard sizes
Nord-Lock Group	Shox Washer	Combined wedge-locking and bushing function
Bossard Group	Proliant SW	High-strength steel (12.9 class)
IKEUCHI	Oiles SPB	Self-lubricating polymer composite

7. Selection Guidelines

Key selection criteria:

Load Requirements: Calculate radial/axial loads using ISO 76:2006 standards
Environmental Factors: Consider operating temperature (-50 C to +300 C range)
Material Compatibility: Prevent galvanic corrosion between mating components
Installation Clearance: Allow 0.5-1.5mm radial play for thermal expansion
Case Study: In wind turbine pitch bearings, stainless steel shoulder washers with solid lubricant pockets demonstrated 40% longer service life versus conventional designs

8. Industry Trends

Emerging development directions:

Material innovation: Graphene-reinforced polymers for weight reduction
Smart integration: Embedded strain sensors for condition monitoring
Manufacturing advancement: Additive manufacturing for complex geometries
Sustainability focus: Bio-based coatings replacing hexavalent chromium
Standardization efforts: ISO/TC 2/SC 12 developing global design standards