Bumper Standoffs

BPF – Female Thread Bumper® Standoffs

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3D CAD Models available. Contact a PENCOM Account Representative to request.

Part Description Example

  • BPFSeries
  • 440Thread
    Code*
  • 1.500Length
  • STLBody
    Material
    Code
  • ZBody
    Finish
    Code

*For 4-40 UNC-2A thread use thread code 440,
for M3 x 0.5 6g thread use thread code M3.

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*Contact a PENCOM Account Representative for the part number based on the description.

Features

  • Female thread allows simple installation using screw and washer without special tools.
  • Installs close to sheet edge without creating any hoop stress in sheet.
bpf-features

Length

Inch

Length
± .010
1.000
1.125
1. 250
1.375
1.500
1. 625
1.750
1. 875
2.000

Metric

Length
± 0.25
26
29
32
35
38
41
44
47
50
bpf-lengthPENCOM carries a broad selection of screw and washer assemblies and components.

Body Material and Finish

Tip Material and Color: Nylon UL94-V0 / White

Body Material CodeBody Material DescriptionBody Finish CodeBody Finish Description
STLCarbon SteelZZinc SC1 with Type III Clear Chromate per ASTM B 633
SS300 -Series Stainless SteelPPassivated and/or Tested per ASTM A 967

Installation

  1. Punch or drill hole in sheet. Insert a male threaded fastener through hole in the sheet and secure the standoff. In some applications it may be desirable to install a washer between the head of the male threaded fastener and sheet.
  2. Tighten the assembly by torquing the male threaded fastener 4.0 to 5.5 in-lbs (4-40) or 0.51 to 0.69 N-m (M3). PENCOM recommends a minimum thread engagement of .112in (4-40) or 3.0mm (M3) between the male and female threads. Installation torques are for zinc-plated Grade 2 (inch) or Class 4.8 (metric) carbon steel screws and for reference only. The majority of joint tightening torque is used to overcome friction under the rotating member face. Many factors can affect the amount of resulting friction such as rotating member surface area and finish, and sheet hole size and finish. PENCOM recommends testing in the application.
  3. Due to the inelastic nature and unpredictable friction coefficients of stainless steel, torque calculations can be unreliable and specifications should be determined through testing.
  4. One method of determining the installation torque uses 50% of the failure torque as developed through testing in the appliation and applying a ±20% tolerance.
bpf-installation

Screw / Washer Options

Follow the examples below to build part descriptions for common screw styles supplied by PENCOM. For the associated part numbers speak with an Account Manager or visit www.pencomsf.com for more screw options. Washer components can be found on page 10 of this bulletin.

Part Description Example

  • M3Thread1
  • X
  • 10Length
  • PHDrive
    Style
    Code
  • PNHead
    Style
    Code
  • MS
  • STLMaterial
    Code
  • ZFinish
    Code
  • IFIMetric
    Standard2

(1) Use 4-40 for 4-40 UNC-2A thread
(2) Screw dimensions per ASME B18.6.7M. Other metric standards available.

Inch

Length
± . 010
3/16
1/4
5/16
3/8
7/16
1/2
9/16
5/8
3/4
7/8
1
1-1/4
1-1/2
1-3/4
2

Metric

Length
± 0.25
3
4
5
6
8
10
12
14
16
18
20
22
25
30
35
Drive Style CodeDescription
PH#1
Cross-recess
SL-PHSlotted #1
Cross-recess
TXT-10
Six-lobe
SL-TXSlotted
T-10 Six-lobe
Head Style CodeDescription
PNPan
FLFlat

Material
Code
Description
STLCarbon Steel
SSStainless Steel

Finish
Code
Description
ZZinc with Clear Chromate

Screw and washer assemblies (SEMS) prevent missing or lost washers and reduce assembly times. The examples below shows the additional codes necessary to modify an M3 screw description (4-40 modification similar).

SEMS washer TypePart Description
External ToothM3X10 PH-PN-EXT-SEMS-MS-STL-Z-IFI
Internal ToothM3X10 PH-PN-INT-SEMS-MS-STL-Z-IFI
Split LockM3X10 PH-PN-SPLT-LK-SEMS-MS-STL-Z-IFI
Square- cone SEMSM3X10 PH-PN-SQCN-SEMS-MS-STL-Z-IFI
Add a nylon patch to the threads to resist loosening.
M3X10 PH-PN-MS-STL-Z-PATCH