Screws, Bolts

Part Number	Description / PDF	Quantity
3404400028 Richco, Inc. (Essentra Components)	HEX SOCKET CAP SCREW, #4-40 THRE	2290
010832W012PC Richco, Inc. (Essentra Components)	PAN PHILLIPS SCREW 8-32 THREAD 1	1000
50M040070I008 Richco, Inc. (Essentra Components)	90 PHILLIPS CSK SCREW, M4 X .7 T	1915
3225020100 Richco, Inc. (Essentra Components)	SLOTTED HEX SCREW, 1/4-20 THREAD	500
50M020040G008 Richco, Inc. (Essentra Components)	FILLISTER PHILLIPS SCREW, M2 X .	2905
010632WF150 Richco, Inc. (Essentra Components)	FILLISTER PHILLIPS SCREW 6-32	0
010632T075 Richco, Inc. (Essentra Components)	SET SCREW SOCKET HEAD 6-32 THREA	900
50M030050M016 Richco, Inc. (Essentra Components)	90 PHILLIPS CSK SCREW, M3 X .5 T	2988
012520CD025 Richco, Inc. (Essentra Components)	BINDER COMBINATION SCREW 1/4-20	0
50M025045I012 Richco, Inc. (Essentra Components)	90 PHILLIPS CSK SCREW, M2.5 X .4	1714
50M100150J016 Richco, Inc. (Essentra Components)	HEX UNSLOTTED BOLT, M8 X 1.25 TH	5000
50M060100D012 Richco, Inc. (Essentra Components)	CHEESE HEAD SLOTTED SCREW, NATUR	14555
012528F018 Richco, Inc. (Essentra Components)	FILLISTER SLOTTED SCREW 1/4-28	0
50M080125J030 Richco, Inc. (Essentra Components)	HEX UNSLOTTED BOLT, M8 X 1.25 TH	4990
012520WF125 Richco, Inc. (Essentra Components)	FILLISTER PHILLIPS SCREW 1/4-20	0
012520PW150 Richco, Inc. (Essentra Components)	PAN PHILLIPS SCREW 1/4-20 THREAD	995
NSS-8-10-01 Richco, Inc. (Essentra Components)	MACH SCREW PAN HEAD SLOTTED 8-32	9600
0337516125 Richco, Inc. (Essentra Components)	UNSLOTTED HEX BOLT 3/8-16 THREAD	995
011032P200 Richco, Inc. (Essentra Components)	PAN SLOTTED SCREW, NATURAL, NYLO	11340
010832S012 Richco, Inc. (Essentra Components)	SET SCREW SLOTTED HEAD 8-32 THRE	990

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