Hex Tap Bolts (Full Thread Hex Cap Screws)

What Are Hex Tap Bolts (Full Thread Hex Cap Screws)?

Hex tap bolts—also called full thread hex cap screws—are hex-head fasteners with threads running the entire length of the shank. They can be used with a nut or driven into a tapped hole when maximum thread engagement through the joint is required.

What Are Hex Tap Bolts (Full Thread Hex Cap Screws) Used For?

• Through-bolting thin or variable material stacks where a partially threaded shoulder would reduce engagement.
• Fastening into pre-tapped holes that require full-depth engagement across the joint thickness.
• Equipment mounting, brackets, guards, and fixtures in machinery and OEM assembly.
• Automotive and repair work, metal-to-metal and wood-to-metal assemblies with a mating nut.

Benefits of Hex Tap Bolts (Full Thread Hex Cap Screws)

• Full engagement: threads span the entire grip for maximum contact in thin or layered joints.
• Versatile fit: works with nuts, tapped plates, and inserts without worrying about shoulder length.
• Standard tools: installs with common wrenches/sockets; easy to remove for service.
• Material choices: available in stainless, silicon bronze, and coated or zinc-plated carbon steel to match environment and appearance.

Hex Tap Bolts (Full Thread Hex Cap Screws) Sizes & Threads

Order by diameter × thread × length (e.g., 3/8"-16 × 2" or M8-1.25 × 50 mm). Inch series commonly use UNC (coarse) or UNF (fine) threads; metric uses standard pitches (e.g., M6-1.0, M8-1.25). Length is measured from under the head to the tip.

Materials & Finishes for Hex Tap Bolts (Full Thread Hex Cap Screws)

• 18-8 / 304 stainless: general corrosion resistance for most outdoor/indoor applications.
• 316 stainless: upgraded resistance for marine and chemically aggressive environments.
• Zinc plated carbon steel: economical protection for dry interior service.
• Silicon bronze: corrosion resistance with a warm appearance for marine/architectural use.
• Metric A2/A4 stainless: the common metric equivalents to 304/316.

Installation Tips for Hex Tap Bolts (Full Thread Hex Cap Screws)

• Match nuts and washers to the bolt’s grade/material and thread (UNC/UNF or metric).
• Select a length that allows 1–3 threads to project beyond the nut after tightening.
• Use appropriate torque methods; for stainless, consider anti-seize to reduce the risk of galling.
• Add flat or flange washers to increase bearing area on softer materials and protect finishes.
• For vibration, consider prevailing-torque lock nuts or a compatible threadlocker.

Related Hardware for Hex Tap Bolts (Full Thread Hex Cap Screws)

• Hex nuts (matching grade/material), nylon-insert lock nuts, and flange nuts
• Flat, fender, and lock washers; finish washers for appearance-critical installs
• Threaded inserts or tapped plates when a nut is not accessible