SIC 3452 Bolts, Nuts, Screws, Rivets, and Washers

SIC 3452

This category includes establishments primarily engaged in manufacturing metal bolts, nuts, screws, rivets, washers, formed and threaded wire goods, and special industrial fasteners. Rolling mills engaged in manufacturing similar products are classified in the major group for primary metal industries (33); establishments primarily engaged in manufacturing screw machine products are classified in SIC 3451: Screw Machine Products; and those manufacturing plastic fasteners are classified in SIC 3089: Plastics Products, Not Elsewhere Classified.

NAICS CODE(S)

332722

Bolt, Nut, Screw, Rivet, and Washer Manufacturing

INDUSTRY SNAPSHOT

Manufacturers in this industry produce the materials that hold American industry together: bolts, nuts, screws, rivets, and washers. Producing these items in lots as small as 1,000 and as large as 20 million, manufacturers make both custom-ordered and standard fasteners using processes quite different from that of the screw machine product industry, SIC 3451: Screw Machine Products, with which it otherwise shares many similarities. While screw machine product manufacturers produce goods using some form of screw machine that cuts into a metal product to produce the needed tooling, fastener manufacturers use a variety of cold-forming and rolling processes to produce simpler parts with greater strength. Both industries trace their beginnings to the early stages of industrialization, which made innovations in the field of fastener engineering possible.

Total industry shipments were valued at $7.6 billion in 2003. The fastener industry is remarkably decentralized, with hundreds of small shops producing the majority of fasteners. Manufacturers in the fastener industry tended to cluster around the industries that purchased its products—traditionally the automotive, defense, and aerospace industries. The industry is therefore concentrated in the auto-producing states of the upper Midwest and the defense and aerospace-oriented regions of California.

ORGANIZATION AND STRUCTURE

Manufacturers in this industry produce a wide and ever-changing variety of products that fall under the general name "industrial fasteners." According to the Industrial Fastener Institute, the trade association for the industry, a fastener is "a mechanical device for holding two or more bodies in definite position with respect to each other. A high percentage of fasteners have threads as part of their design, but unthreaded items such as rivets, clevis pins, machine pins, etc., are considered fasteners as well." The industry produces fasteners using the primary manufacturing operations of heading, upsetting, forming, forging, and extruding. Fasteners primarily use ferrous metals for products, usually carbon and alloy steels. Most fasteners begin as wire, rod, or bar, which is cut to length, headed, and then threaded.

A typical hex-head bolt begins as a shaft of metal whose length is a number of times longer than its diameter. This shaft is placed in a die, a metal holder that maintains the shaft's position when it is struck by a punch, which is designed to impart the hexagonal shape of a bolt head to the shaft. Multiple punches are sometimes used to impart more intricate head shapes or to form harder metals. The headed shaft is then given an external thread in another cold-forming process called thread rolling. In thread rolling, the headed shaft is pressed between stationary and moving hardened-steel dies, which squeeze the material into the desired thread form. The nut that accompanies this bolt may also be cold-formed using a thread-forming tap that displaces rather than removes metal to form the interior thread. These and other processes like them constitute the major means by which industrial manufacturers produce goods.

According to the Manufacturers' Capability Guide, published by the Industrial Fastener Institute, "Cold forming is a high-speed, high-volume production process, with economical production rates determined by part size, design complexity, and degree of forming required—all factors that determine the number of blows required to form the part and thus the complexity of the tooling and equipment required." Cold-forming has the advantage of allowing the manufacturer to produce many thousands of products an hour. According to John E. Neely and...

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