What Are 7 Types of Fasteners?

In the intricate world of manufacturing and assembly, fasteners are indispensable. These small components often go unnoticed, but they hold together the very structures we rely on—from automobiles to airplanes, bridges to buildings. Behind their precise shapes and uniform strength lies an essential industrial process: the creation of fastener molds. These molds serve as the backbone of mass fastener production, ensuring consistency, strength, and adaptability across applications.

This article dives deep into what fastener molds are, why they matter, and explores seven common types of fasteners used across various industries. Whether you're an engineer, manufacturer, or simply curious about industrial hardware, this guide will provide clarity, detail, and practical insight.

What Are Fastener Molds?

Fastener molds are high-precision tools used to manufacture fasteners such as bolts, screws, nuts, rivets, and washers. These molds are typically made from durable, heat-resistant materials like hardened steel or tungsten carbide, designed to withstand repetitive high-pressure molding processes. The goal of a fastener mold is to reproduce fasteners with precise dimensions, tolerances, and structural integrity.

Key Characteristics of Fastener Molds

• Durability: Designed to endure thousands of molding cycles.

• Accuracy: Produces fasteners within microns of dimensional tolerance.

• Flexibility: Customizable for various head shapes, threading types, and shaft lengths.

• Efficiency: Reduces production time through high-speed operations.

Fastener molds are widely used in cold heading and hot forging processes, where metal wire is shaped under immense pressure. Once molded, the fasteners may undergo threading, heat treatment, or surface coating depending on their application.

Type 1 – Bolts

Structure and Application

Bolts are one of the most commonly used types of fasteners, characterized by their cylindrical shape, threaded shaft, and hexagonal or square head. They require a matching nut to secure materials together. Fastener molds used to produce bolts must maintain uniform thread pitch and depth, ensuring secure fits and reliable torque resistance.

Common Uses of Bolts

• Construction: Securing beams and structural elements.

• Machinery: Holding machine parts under vibration.

• Automotive: Assembly of engine components and chassis.

A well-designed bolt mold ensures each piece meets industry-specific standards such as ISO, DIN, or ANSI. The mold's performance directly affects bolt strength, fatigue resistance, and thread alignment.

Type 2 – Screws

Threaded Precision

Unlike bolts, screws are typically used without nuts and are designed to embed directly into materials such as wood, metal, or plastic. Their helical threading creates friction and pull-out resistance. Molds for screws must be engineered to form sharp, continuous threads with specific angles, depths, and pitches.

Variations of Screws

• Wood Screws

• Self-tapping Screws

• Machine Screws

• Sheet Metal Screws

Screw molds must take into account material shrinkage, metal flow behavior, and tip geometry, especially for self-drilling types. Precision in screw molding ensures effective grip and structural integrity, especially in load-bearing applications.

Type 3 – Nuts

Internal Threading Mastery

Nuts are internally threaded fasteners that pair with bolts to clamp objects together. They come in various shapes, including hex nuts, wing nuts, and lock nuts. The key to an effective nut mold lies in the accurate creation of internal threads, which must perfectly match bolt specifications.

Challenges in Nut Mold Design

• Thread alignment for high-speed assembly.

• Material strength to prevent stripping.

• Surface finish for anti-corrosion treatment compatibility.

Using fastener molds for nuts often involves multiple stages, including core insert creation, thread forming, and surface finishing processes like shot blasting or coating. These steps ensure durability and usability across different environments.

Type 4 – Washers

Flat but Critical

Often overlooked, washers serve to distribute the load of threaded fasteners and prevent damage to the joining surfaces. There are several types, including flat, spring, and locking washers. Molds for washers must achieve perfect symmetry, thickness uniformity, and edge smoothness.

Material and Tolerance Considerations

• Materials: Stainless steel, brass, rubber.

• Thickness: Ranges from fractions of millimeters to several mm.

• Tolerance: Must fit precisely within bolt and nut configurations.

Washer molds are typically produced using stamping or die-cutting, and require minimal deviation to avoid imbalanced load distribution.

Type 5 – Rivets

Permanent Joint Solutions

Rivets are permanent mechanical fasteners that join two materials by deforming the tail end after insertion. Common in aerospace, shipbuilding, and structural steel applications, rivets must be manufactured to exact dimensions to allow for clean deformation and reliable holding force.

Rivet Mold Features

• Head shape precision: Round, flat, or countersunk.

• Shaft uniformity: Ensures consistent drive-through force.

• Tolerance: Extremely low for aerospace-grade rivets.

Fastener molds for rivets are usually built for high-speed press machines and are tested for wear resistance and dimensional repeatability.

Type 6 – Pins

Alignment and Positioning

Pins such as dowel pins, clevis pins, and cotter pins are used to align or join components. They may not always feature threads, relying instead on friction, deformation, or mechanical locking. Fastener molds for pins must deliver high straightness, surface finish, and consistent diameter.

Applications

• Gears and pulleys

• Automotive steering

• Tool assembly

Pin molding often involves multi-cavity molds to speed production. Material selection for pin molds also depends on required hardness and resistance to shearing forces.

Type 7 – Anchors

For Structural Integrity

Anchors are specialized fasteners used to secure objects to concrete, masonry, or drywall. They expand or embed into the base material upon installation. Producing anchors requires molds with features that allow for undercuts, serrations, or internal voids.

Types of Anchors

• Expansion Anchors

• Chemical Anchors

• Sleeve Anchors

Molds for anchors must enable precise overmolding or split-part design to achieve expansion mechanisms. These are typically used in building construction, bridge repairs, and heavy-duty shelving systems.

Comparative Table – Overview of 7 Fastener Types

FAQ Section

What materials are used for fastener molds?

Typically, fastener molds are made from hardened tool steels, tungsten carbide, or high-speed steels to endure extreme pressures and ensure long mold life.

How are fastener molds maintained?

Routine maintenance includes cleaning, polishing, re-hardening, and dimensional inspection to prevent defects and ensure consistent output.

Can one mold produce multiple types of fasteners?

No, molds are generally customized for each fastener type due to variations in shape, threading, and mechanical function.

Conclusion

Fastener molds are silent workhorses behind the fasteners that hold our world together. Their precision, design, and resilience directly influence the quality of the end product. Understanding the types of fasteners—bolts, screws, nuts, washers, rivets, pins, and anchors—not only enhances product design but also guides decisions in sourcing, maintenance, and quality control. By investing in high-quality fastener molds, manufacturers gain not just parts—but precision, performance, and reliability.