Screws, Bolts

Part Number	Description / PDF	Quantity
PMS 832 0038 SL B&F Fastener Supply	MACH SCREW PAN HEAD SLOTTED 8-32	142
PMS 832 0025 SL B&F Fastener Supply	MACH SCREW PAN HEAD SLOTTED 8-32	153900
PMSSS 440 0075 PH B&F Fastener Supply	MACHINE SCREW PAN PHILLIPS 4-40	4100
HMSSS 440 0100 B&F Fastener Supply	MACH SCREW HEX #4-40	200
4X1/2 PHSMSPH B&F Fastener Supply	SHT METAL SCREW PAN PHILLIPS #4	2800
HMSSS 632 0088 B&F Fastener Supply	MACH SCREW HEX #6-32	40
PMS 632 0025 SL B&F Fastener Supply	MACH SCREW PAN HEAD SLOTTED 6-32	4600
HHSS 025 0075 20 B&F Fastener Supply	CAP SCREW HEX 1/4"-20	20
HMSSS 632 0025 B&F Fastener Supply	MACH SCREW HEX #6-32	1130
PMS 632 0038 PH B&F Fastener Supply	MACHINE SCREW PAN PHILLIPS 6-32	16000
HHSS 038 0075 16 B&F Fastener Supply	CAP SCREW HEX 3/8"-16	520
HMSSS 102 0100 B&F Fastener Supply	MACH SCREW HEX #10-32	380
HMSSS 632 0150 B&F Fastener Supply	MACH SCREW HEX #6-32	70
PMS 440 0025 SL B&F Fastener Supply	MACH SCREW PAN HEAD SLOTTED 4-40	1800
HHSS 031 0100 18 B&F Fastener Supply	CAP SCREW HEX 5/16"-18	580
PMS 440 0031 PH B&F Fastener Supply	MACHINE SCREW PAN PHILLIPS 4-40	3400
PMS 256 0025 SL B&F Fastener Supply	MACH SCREW PAN HEAD SLOTTED 2-56	9000
MPMS 003 0008 PH B&F Fastener Supply	MACH SCREW PAN HEAD PHILLIPS M3	0
HHSS 038 0150 16 B&F Fastener Supply	CAP SCREW HEX 3/8"-16	870
PMS 440 0050 PH B&F Fastener Supply	MACHINE SCREW PAN PHILLIPS 4-40	12800

Screws, Bolts

1. Overview

Screws and bolts are threaded fasteners designed to mechanically join materials. Defined by their helical threads and head configurations, these components enable removable or permanent assemblies in engineering applications. Their importance in modern technology stems from their ability to provide high clamping forces, ease of installation, and adaptability across industries ranging from aerospace to consumer electronics.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Hex Bolt	High torque transmission, hexagonal head for wrenching	Structural steel connections in construction
Socket Head Cap Screw	Internal hex drive, cylindrical head for precise torque	Machinery assemblies requiring flush mounting
Self-Tapping Screw	Drills own thread in mating material during installation	Metal sheet joining in HVAC systems
Carriage Bolt	Dome head with square neck to prevent rotation	Wood-to-metal fastening in furniture
Anchor Bolt	Expandable end for concrete substrate anchoring	Foundation connections in industrial equipment

3. Structure and Composition

Typical configurations include: - Head (hexagonal, cylindrical, or countersunk) - Bearing surface (under-head contact area) - Shank (unthreaded cylindrical section) - Threaded portion (metric or imperial pitch) - Point (tapered or blunt end) Materials range from carbon steel (grades 4.8-12.9) to stainless steel (A2/A4), titanium, and specialty alloys. Surface treatments include zinc plating, galvanization, and phosphate coatings.

4. Key Technical Parameters

Parameter	Significance
Tensile Strength (MPa)	Determines maximum axial load capacity
Proof Load (MPa)	Maximum stress before plastic deformation
Hardness (HV/HRC)	Indicates wear resistance and brittleness
Thread Pitch (mm/TPI)	Dictates engagement quality and assembly speed
Corrosion Resistance Class	Measured by salt spray test hours (e.g., ISO 9227)

5. Application Fields

Automotive: Cylinder head bolts (torque-to-yield), wheel studs
Aerospace: NAS/AN standard fasteners in airframe assemblies
Construction: M20+ diameter bolts in steel bridges
Electronics: 0-80 UNF screws in circuit board mounting
Renewables: Wind turbine tower segment connections

6. Leading Manufacturers

Manufacturer	Key Products
Hilti Corporation	HIT-HY 150 MAX adhesive anchors
Bossard Group	Delta PT self-tapping screws for aluminum
Stanley Black & Decker	FASTORQ structural hex bolts
ARaymond	Push-on quick-connect fasteners for automotive

7. Selection Guidelines

Key considerations:

Material compatibility (e.g., stainless steel in marine environments)
Load requirements (static vs. dynamic loading conditions)
Environmental exposure (temperature range, chemical contact)
Installation method (manual vs. automated torque-controlled tools)
Cost optimization (balance between performance and budget)

Example: Selecting A4-70 stainless bolts for coastal infrastructure projects ensures seawater resistance while maintaining 700MPa tensile strength.

8. Industry Trends

Current developments include:

Hybrid composite fasteners for weight reduction in EVs
Smart bolts with embedded strain sensors (IoT integration)
Self-lubricating coatings reducing installation torque variability
Additive manufacturing of customized thread profiles
Sustainability initiatives: Recyclable alloy development and process energy reduction