PEM Standoffs For Sheet Metal & Key Meaning

Fasteners are hardware devices that mechanically join or affix two or more objects together. They are used to create non-permanent joints, as opposed to welding.
This article summarizes common PEM fasteners, standoffs .Which provide threaded inserts and mounting points for sheet metal parts and PC boards.

  • Concealed-Head – CSOS, CSS
  • Keyhole® – SKC, SK4
  • Blind, Threaded – BSO, BSO4, BSOA, BSOS
  • Thru-hole, Threaded and Unthreaded – SO, SO4, SOA, SOS
  • For Installing Into Stainless – BSO4, SO4, TSO4
  • Thin Sheet, Thru-hole Standoffs – TSO, TSOA, TSOS
  • Snap-Top® – SSA, SSC, SSS
  • Grounding – SOAG, SOSG
  • Close-To-Edge – DSO, DSOS
  • microPEM®, Self-Clinching – MSO4, MSOFS
  • Thin Sheet, Thru-hole Standoffs for Installation into Stainless Steel- TSO4

Concealed Head Standoffs – Types CSOS, CSS

PEM® self-clinching concealed-head standoffs install permanently in steel or aluminum sheets as this as .062″ / 1.6mm. This feature allows the side of the sheet opposite installation to remain smooth and untouched.

CSOS –300 Series Stainless Steel
CSS– 300 Series Stainless Steel

KEYHOLE® Standoffs – Types SKC, SK4


PEM® KEYHOLE® standoffs are designed so that a PC board or panel can be quickly slipped into place and then removed from an assembly by simply sliding the board sideways and lifting it off. Type SKC can be used for spacing or hanging of replaceable components.

SKC –300 Series Stainless Steel

Blind, Threaded – Types BSO, BSO4, BSOA, BSOS


These standoffs are designed for spacing applications where outer sheet surfaces must be flush and closed for smoother sheet appearance.

CSOS –300 Series Stainless Steel
CSS– 300 Series Stainless SteelBSO – Heat-Treated Carbon Steel
BSO4 – 400 Series Stainless Steel
BSOA – Aluminum
BSOS – 300 Series Stainless Steel

Thru-hole, Threaded and Unthreaded- Types SO, SO4, SOA, SOS


PEM® brand thru-hole threaded standoffs are installed with their heads flush with one surface of the mounting sheet. Unthreaded standoffs are also available for spacing multi-panel assemblies.

SO – Heat-Treated Carbon Steel
SO4 – 400 Series Stainless Steel
SOA – Aluminum
SOS – 300 Series Stainless Steel

Install Into Stainless – Types BSO4, SO4, TSO4


Types BSO4 and SO4 standoffs are for installation into stainless steel sheets as thin as .040 ” / 1.02 mm.

SO – Heat-Treated Carbon Steel
SO4 – 400 Series Stainless Steel
SOA – Aluminum
SOS – 300 Series Stainless Steel

Thin Sheet, Thru-Hole – Types TSO, TSOA, TSOS, TSO4

Types TSO, TSOS, TSOA and TSO4 self-clinching threaded standoffs provide permanent threads in sheets as thin as .025 ” / 0.63 mm.

TSO – Heat-Treated Carbon Steel
TSOA – 400 Series Stainless Steel
TSOS – Aluminum



PEM® SNAP-TOP® standoffs use a spring action to hold PC boards and subassemblies securely, while allowing for quick removal. Screws and other threaded hardware are eliminated.

SSA – Aluminum
SSC – 400 Series Stainless Steel
SSS – Heat-Treated Carbon Steel

Grounding – Types SOAG, SOSG


Types SOAG and SOSG grounding standoffs are designed for clinching into steel or aluminum chassis while the “gripping teeth” on the opposite end of the standoff firmly contact mating PC board.

SOAG – Aluminum
SOSG – Stainless Steel

Close To Edge – Types DSO, DSOS


Types DSO and DSOS standoffs are available for close-to-edge applications.

DSO – Heat-Treated Carbon Steel
DSOS – 300 Series Stainless Steel

Micro, Self-Clinching – Types MSO4™, MSOFS™

Type MSO4 micro standoffs are designed for mounting /spacing in extremely limited space applications. Type MSOFS micro flaring standoffs attach permanently in any type of panel, including metal, plastic and P.C. Board.

MSO4 – 400 Series Stainless Steel
MSOFS – 300 Series Stainless Steel

Read more about RpProto’s sheet metal fabrication service.  ->

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