Enhanced Drive Performance
The external lobed drive system offers better engagement between the fastener and driver, helping reduce cam-out and improve installation efficiency.
ASME/ANSI B 18.2.1-9 Lobed Head Screws
- Standard: ASME/ANSI B 18.2.1-9
- Material: Stainless Steel
- Thread Size: 1/4 – (1-3/8)
- Surface Treatment: Plain, Zinc Plated
- Min Order: 5000pcs
- Sample: Free sample (after quote)
- Delivery time: 30 – 45 Days
Product Overview
Product Application
ASME B18.2.1-9 Lobed Head Screws are inch-series fasteners with a specially designed external lobed drive head. They are covered under ASME B18.2.1 (Table 9), which specifies dimensional requirements for lobed head screw designs, including head dimensions, drive geometry, and thread specifications.
The lobed head design provides improved torque transmission and reduced risk of driver slip compared with conventional screw heads, making it suitable for applications requiring secure fastening and controlled assembly.
Draw
Specification
Lobed Head Screws vs Hex Cap Screws
Drive Design
Lobed Head Screws:
Feature a specialized lobed drive profile for improved engagement and controlled torque application.
Hex Cap Screws:
Use a traditional hexagonal head requiring a wrench or socket for installation.
Installation Efficiency
Lobed Head Screws:
Provide smoother power-tool operation with reduced slipping during assembly.
Hex Cap Screws:
Suitable for general applications but may experience tool slip under excessive torque.
Application Focus
Lobed Head Screws:
Preferred where secure fastening, repeat assembly, or tamper resistance is required.
Hex Cap Screws:
Widely used for standard mechanical fastening applications.
Product Advantages
Improved Security & Reliability
The unique lobed profile provides higher resistance to unauthorized removal and helps maintain fastening integrity in vibration-prone applications.
Standardized Inch Dimensions
Manufactured according to ASME B18.2.1 dimensional requirements, ensuring consistent interchangeability and compatibility with standard assemblies.
Common Questions
What is an ASME B18.2.1-9 Lobed Head Screw?
It is a screw manufactured according to ASME B18.2.1 Table 9 requirements, featuring a lobed head design for improved drive engagement and fastening performance.
What is the advantage of a lobed head design?
The lobed profile improves torque transfer, reduces driver slipping, and provides more reliable installation compared with traditional drive designs.
Are Lobed Head Screws interchangeable with hex screws?
No. Although both are covered within ASME B18.2.1, lobed head screws use a different head and drive configuration and require compatible tooling.
Can ASME B18.2.1-9 Lobed Head Screw be customized?
Yes. Manufacturers can provide customized materials, coatings, lengths, thread specifications, and packaging according to project requirements.
