Board Spacers, Standoffs

Part Number	Description / PDF	Quantity
R40-6711294 Harwin	ROUND SPACER M4 NYLON 12MM	4534
M1802-A-2545-SS-20 RAF	4.5MM RD X 5MM X M2.5 THD	400
24398 Keystone Electronics Corp.	HEX STANDOFF M3 BRASS 25MM	200
2059-440-S-12 RAF	HEX STANDOFF #4-40 STEEL 5/8"	730
1893-1032-N RAF	1/2_ROUND_FEMALE_STANDOFFS	900
4500-440-AL-6 RAF	3/16 HEX X 3/16 LENGTH	250
M2103-3005-SS-20 RAF	4.5MM HEX X 8MM X M3 THD	275
971600581 Würth Elektronik Midcom	HEX STANDOFF M5 STEEL 60MM	52
1029-093-SS RAF	17/32OD X 10-32 THD	184
970090361 Würth Elektronik Midcom	HEX SPACER M3X0.5 STEEL 9MM	0
R937-1 Richco, Inc. (Essentra Components)	ROUND SPACER NYLON 1/16"	5990
970120361 Würth Elektronik Midcom	HEX SPACER M3X0.5 STEEL 12MM	100
2070-440-AL RAF	HEX STANDOFF #4-40 ALUM 1-5/16"	320
1123-4-N RAF	ROUND SPACER NYLON 3/16"	779
13RS062589 Richco, Inc. (Essentra Components)	ROUND SPACER, .250 ID, .625 OD,	1961
1104-2-N RAF	1/8 RD X 3/8 X .090 ID	1715
NAS1829C4F16 RAF	STAINLESS STEEL 1/4 HEX MALE/FEM	250
13SPRT059 Richco, Inc. (Essentra Components)	ROUND SPACER, RETAINING, #4 SCRE	2000
960110042 Würth Elektronik Midcom	ROUND PLASTIC SPACER L:11,0 MM	309
4189-1032-SS RAF	1/2 RD X 1-1/2 LENGTH	135

Board Spacers, Standoffs

1. Overview

Board spacers and standoffs are specialized hardware components used to create controlled spacing between printed circuit boards (PCBs), panels, or structural elements. They provide mechanical support, electrical isolation, and thermal management in electronic assemblies. Their importance in modern technology includes enabling compact designs, reducing vibration stress, and improving heat dissipation in devices ranging from smartphones to industrial control systems.

2. Main Types & Functional Classification

Type	Functional Features	Application Examples
Cylindrical Spacers	Simple tubular design with uniform diameter	PCB layer separation in consumer electronics
Hexagonal Standoffs	6-sided structure for wrench tightening	Industrial equipment panel mounting
Self-clinching Standoffs	Permanent installation with threaded compression	Sheet metal enclosures in servers
Adjustable Spacers	Variable length through threaded adjustment	Prototype development and testing
Insulated Spacers	Non-conductive materials for electrical isolation	High-voltage power supply assemblies

3. Structure & Composition

Typical construction includes:

Material: Stainless steel (corrosion resistance), aluminum (lightweight), or nylon (insulation)
Geometry: Cylindrical (standard), stepped (for multiple board heights), or flanged (for load distribution)
Installation Features: Internal threading (male/female), knurled surfaces (for grip), or press-fit tabs
Surface Treatment: Passivation (metal), UV resistance (plastics), or EMI shielding coating

4. Key Technical Specifications

Parameter	Importance
Material Hardness (HV)	Determines wear resistance and load capacity
Thread Engagement Length	Affects vibration resistance in dynamic environments
Thermal Conductivity (W/m K)	Critical for heat dissipation in power electronics
Dielectric Strength (kV/mm)	Safety factor in high-voltage applications
Installation Torque Rating	Prevents over-tightening damage to PCBs

5. Application Fields

Primary industries include:

Electronics Manufacturing: Server racks, LED displays
Automotive: Engine control units (ECUs), ADAS systems
Aerospace: Satellite PCB mounting, avionics enclosures
Medical Devices: MRI scanner internal structures
Consumer Electronics: Smartphone PCB stacking

6. Leading Manufacturers & Products

Manufacturer	Representative Product
PEM	S-8900 Series self-clinching standoffs
RS Components	486-8826 insulated hexagonal spacers
Mouser Electronics	925206-12 adjustable PCB spacers
McMaster-Carr	91285A102 stainless steel standoffs

7. Selection Recommendations

Evaluate mechanical load requirements vs material strength
Match thread type (UNC/UNF/Metric) with assembly hardware
Consider CTE (Coefficient of Thermal Expansion) compatibility with PCB materials
Select insulated variants for >50V circuits
Use vibration-damping coatings in mobile applications

8. Industry Trends

Emerging developments include:

Miniaturization: Sub-1mm spacers for wearable devices
Material Innovation: Conductive polymer composites for EMI shielding
Smart Integration: Standoffs with embedded strain gauges for structural monitoring
Automated Installation: Self-aligning designs for robotic assembly lines
Sustainability: Biodegradable plastic options (PLA-based) entering mainstream production