Board Spacers, Standoffs

Part Number	Description / PDF	Quantity
1547A Keystone Electronics Corp.	ROUND STANDOFF #4-40 BRASS 1/4"	25
1549E Keystone Electronics Corp.	ROUND STANDOFF #8-32 BRASS 1"	27657
1623-2 Keystone Electronics Corp.	ROUND STANDOFF #4-40 BRASS 1/2"	550
24393 Keystone Electronics Corp.	HEX STANDOFF M3 BRASS 10MM	24543200
1922A Keystone Electronics Corp.	HEX STANDOFF #6-32 SS 3/8"	5083354
24421 Keystone Electronics Corp.	HEX STANDOFF M2.5X0.45 ALUM 6MM	47502500
24475 Keystone Electronics Corp.	HEX STANDOFF M3 SS 15MM	87328
1653-2 Keystone Electronics Corp.	HEX STANDOFF #4-40 BRASS 1/8"	15198100
1822B Keystone Electronics Corp.	HEX STANDOFF #10-32 BRASS 1/2"	5952084
1902C Keystone Electronics Corp.	HEX STANDOFF #4-40 NYLON 1/2"	198682400
24385 Keystone Electronics Corp.	HEX STNDFF M2.5X0.45 BRASS 15MM	2432200
8408 Keystone Electronics Corp.	HEX STANDOFF #4-40 ALUM 1-3/8"	398600
25509 Keystone Electronics Corp.	HEX STANDOFF M3 NYLON 8MM	0
5064-3 Keystone Electronics Corp.	ROUND SPACER #6 BRASS 3/8"	12502200
24448 Keystone Electronics Corp.	HEX STANDOFF M3 ALUMINUM 25MM	98575000
1650-3 Keystone Electronics Corp.	ROUND STANDOFF #4-40 BRASS 1/4"	48962100
24340 Keystone Electronics Corp.	HEX STANDOFF M3 ALUMINUM 18MM	74724000
1656A Keystone Electronics Corp.	HEX STANDOFF #4-40 BRASS 3/4"	61192600
1921E Keystone Electronics Corp.	HEX STANDOFF #4-40 SS 1-1/2"	1991987
24338 Keystone Electronics Corp.	HEX STANDOFF M3 ALUMINUM 12MM	9953200

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