Closed-end self-clinching standoff for threaded fastening in sheet metal. Available in zinc-plated steel (type CFBSO) and A2 stainless steel (type CFBSOS). Ideal for applications requiring sealing or insulation.
What is a blind self-clinching standoff?
A blind self-clinching standoff is a mechanical fastener cold-installed by pressing it into a pre-drilled hole. Its tubular design, closed end and internal thread create a threaded fastening that does not pass through the sheet, providing a seal against fluids, dirt and external contaminants.
Unlike a through-hole self-clinching standoff, a blind standoff has a closed lower end, making it ideal where sealing or insulation is required. It is widely used in electronics, automotive applications, household appliances and metal furniture.
Technical features
- Cold installation by press-fitting into a pre-drilled hole.
- External serrations ensure robust anchoring.
- Closed end prevents the passage of fluids, dirt and external contaminants.
- Internal thread for securely fastening components.
- Applications: electronic equipment, automotive, household appliances, metal furniture and metalwork.
- Available materials: zinc-plated steel (type CFBSO) and A2 stainless steel (type CFBSOS).
- Finish: corrosion-protected zinc-plated steel · A2 stainless steel for outdoor and damp environments.
Advantages of using separadores insertables ciegos
- Quick and simple installation without tapping the sheet beforehand.
- Provide a strong, durable metal thread in thin sheet.
- Closed end prevents the passage of fluids, dirt and external contaminants.
- High torque-out resistance thanks to the serrated design.
- Available in two materials for different environments: indoor (zinc-plated) and outdoor or damp (stainless steel).
- Thread sizes from M2.5 to M6 for a wide range of applications.
- Several lengths available to suit the sheet thickness.
Dimensions and codes by thread size
Metric M2.5
Blind self-clinching standoff with a 2,5 mm thread diameter. Ideal for light-duty fastening in electronic equipment and small components.
- Type CFBSO (zinc-plated steel) · Type CFBSOS (A2 stainless steel)
- Available L lengths: 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 mm
- Minimum sheet thickness: 1 mm
- Hole size: 4,22 mm
- C (outside diameter): 4,2 mm
- H (nominal height): 4,75 mm
- Minimum edge distance: 6 mm
- Minimum thread depth (F): 3,2 mm
Metric M3
Blind self-clinching standoff with a 3 mm thread diameter. One of the most widely used thread sizes for fastening electronic components and housings.
- Type CFBSO (zinc-plated steel) · Type CFBSOS (A2 stainless steel)
- Available L lengths: 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 mm
- Minimum sheet thickness: 1 mm
- Hole size: 4,22 mm
- C (outside diameter): 4,2 mm
- H (nominal height): 4,75 mm
- Minimum edge distance: 6 mm
- Minimum thread depth (F): 4 mm
Metric M3.5
Blind self-clinching standoff with a 3,5 mm thread diameter. Provides a larger thread surface than M3 without reaching the size of M4.
- Type CFBSO (zinc-plated steel) · Type CFBSOS (A2 stainless steel)
- Available L lengths: 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 mm
- Minimum sheet thickness: 1 mm
- Hole size: 5,41 mm
- C (outside diameter): 5,39 mm
- H (nominal height): 6,35 mm
- Minimum edge distance: 6 mm
- Minimum thread depth (F): 4 mm
Metric M4
Blind self-clinching standoff with a 4 mm thread diameter. Widely used in metal furniture and household appliances.
- Type CFBSO (zinc-plated steel) · Type CFBSOS (A2 stainless steel)
- Available L lengths: 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 mm
- Minimum sheet thickness: 1,27 mm
- Hole size: 6 mm
- C (outside diameter): 5,98 mm
- H (nominal height): 7 mm
- Minimum edge distance: 7,5 mm
- Minimum thread depth (F): 5 mm
Metric M5
Blind self-clinching standoff with a 5 mm thread diameter. Ideal for medium-load applications in metal structures.
- Type CFBSO (zinc-plated steel) · Type CFBSOS (A2 stainless steel)
- Available L lengths: 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 mm
- Minimum sheet thickness: 1,27 mm
- Hole size: 7,14 mm
- C (outside diameter): 7,12 mm
- H (nominal height): 8 mm
- Minimum edge distance: 8 mm
- Minimum thread depth (F): 6,5 mm
Metric M6
Blind self-clinching standoff with a 6 mm thread diameter. For applications requiring robust fastening in thicker sheet.
- Type CFBSO (zinc-plated steel) · Type CFBSOS (A2 stainless steel)
- Available L lengths: 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 mm
- Minimum sheet thickness: 1,3 mm
- Hole size: 8,75 mm
- C (outside diameter): 8,72 mm
- H (nominal height): 10 mm
- Minimum edge distance: 9 mm
- Minimum thread depth (F): 9,5 mm
Summary dimensions table
| Metric | Type | L lengths (mm) | Min. sheet thickness (mm) | Hole size (mm) | C (mm) | H (mm) | Edge distance (mm) | Min. F (mm) |
|---|---|---|---|---|---|---|---|---|
| M2.5 | CFBSO / CFBSOS | 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 | 1 | 4,22 | 4,2 | 4,75 | 6 | 3,2 |
| M3 | CFBSO / CFBSOS | 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 | 1 | 4,22 | 4,2 | 4,75 | 6 | 4 |
| M3.5 | CFBSO / CFBSOS | 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 | 1 | 5,41 | 5,39 | 6,35 | 6 | 4 |
| M4 | CFBSO / CFBSOS | 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 | 1,27 | 6 | 5,98 | 7 | 7,5 | 5 |
| M5 | CFBSO / CFBSOS | 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 | 1,27 | 7,14 | 7,12 | 8 | 8 | 6,5 |
| M6 | CFBSO / CFBSOS | 6, 8, 10, 12, 14, 16, 18, 20, 22, 25 | 1,3 | 8,75 | 8,72 | 10 | 9 | 9,5 |
Measurement key
- L: Overall length of the blind self-clinching standoff.
- C: Outside diameter of the self-clinching standoff.
- H: Nominal height of the self-clinching standoff.
- F mín.: Minimum available internal thread depth.
- Hole size: Diameter of the hole to be drilled in the sheet for installation.
- Minimum sheet thickness: Minimum recommended thickness to ensure correct anchoring.
- Minimum edge distance: Minimum recommended distance from the hole centre to the sheet edge.
Available materials
- Type CFBSO (zinc-plated steel): Corrosion protection for indoor and dry environments. Bright finish.
- Type CFBSOS (A2 stainless steel): Corrosion-resistant and suitable for outdoor, damp or saline environments.
Typical applications
- Fastening electronic components and housings where sealing is required.
- Joining panels and profiles in metal furniture.
- Chassis and bodywork in the automotive industry.
- Household appliances and industrial machinery.
- Lightweight structures and quick-fastening systems.
- Applications where the passage of fluids or dirt must be prevented.
Difference between blind and through-hole standoffs
- Blind standoff (CFBSO/CFBSOS): Its lower end is closed, preventing the passage of fluids, dirt and external contaminants. Ideal where sealing or insulation is required.
- Through-hole standoff (CFSO/CFSOS): It has a fully open bore, allowing the screw to pass through the entire component. Ideal for fastening components from both sides of the sheet.
How to order your blind self-clinching standoff
Select the type (CFBSO for zinc-plated steel or CFBSOS for A2 stainless steel), thread size and L length according to the table.
Order example: CFBSO M4 L12 (M4 blind self-clinching standoff, zinc-plated steel, 12 mm long)