Product Description
4BA Zinc Plated Steel Round Head Slotted Machine Screws
These 4BA machine screws are manufactured from zinc plated steel and feature a traditional domed round head with a single slotted drive. The rounded head remains visible above the mounting surface, providing an attractive traditional appearance for restoration and engineering applications.
The British Association thread makes these screws particularly suitable for repairing vintage machinery, electrical equipment, instruments, model engineering projects and other assemblies originally manufactured with BA fasteners.
Product Specifications
- Thread size: 4BA
- Nominal thread diameter: 3.6mm / approximately 0.142 inch
- Thread pitch: 0.66mm
- Threads per inch: Approximately 38.5 TPI
- Thread angle: 47.5°
- Material: Steel
- Finish: Zinc plated
- Head style: Round head
- Drive type: Slotted
- Thread series: British Association
- Applicable product standard: BS 57:1951
- Thread standard: BS 93:2008
Available Size
| Thread Size | Length | Thread Pitch | Approximate TPI |
|---|---|---|---|
| 4BA | 3/8 inch | 0.66mm | 38.5 TPI |
Length measurement: Round head machine screw lengths are measured from underneath the head to the end of the screw. The head is not included in the stated length.
Typical Applications
- Vintage machinery and equipment
- Electrical terminals and switchgear
- Instrumentation and control equipment
- Model engineering projects
- Automotive and motorcycle restoration
- Repairs to traditional British-made assemblies
Installation Information
Install using a correctly sized flat-bladed screwdriver and a matching 4BA nut or internally threaded component. BA threads use a distinctive 47.5° thread angle and must not be substituted with superficially similar metric or Unified fasteners.
The zinc plated finish provides improved corrosion resistance compared with untreated steel. These screws are best suited to internal or generally dry applications rather than prolonged exposure to severe outdoor or marine environments.
Browse our complete ranges of machine screws, compatible nuts and washers.
Please note: Specifications are provided as a guide. If dimensions or standards compliance are critical to your application, please contact us before ordering.
| A | B | C | D | E |
| 4BA | 3/8" | * | * | 38.5 |
Please Note: Specifications given are intended as a guide only. If critical to your project please check with us first.
