What this kit is A 16-piece, zinc-finish steel mounting kit that secures one plate-mount caster to a 3/8"-16 bolt-pattern equipment frame. Includes 4 carriage bolts, 4 hex thread-cutting screws, 4 SAE flat washers, and 4 nylon-insert lock nuts. Engineered for industrial cart, dolly, tool-box, and material-handling applications where a 3/8" bolt diameter matches the caster top plate. Kit Specifications Pieces per kit 16 (4 of each component) Mounts 1 plate-mount caster Thread spec 3/8"-16 UNC Bolt length 1" Material Low-carbon steel Finish Zinc plated Bolt grade ASTM A307 Grade A (carriage bolts) Nut type Grade 2 nylon-insert lock nut Washer type SAE general-purpose flat washer Application Indoor industrial; dry environments What's Included (16 pieces total) 4 × 3/8"-16 × 1" hex-slotted drive indented hex washer head Type F point thread-cutting screws, zinc finish, low-carbon steel — for self-tapping installation into thin-wall steel frames 4 × 3/8"-16 × 1" round-head carriage bolts, zinc finish, ASTM A307 Grade A — for through-bolting to wood, fabricated steel, or pre-drilled equipment 4 × 3/8" SAE general-purpose flat washers, zinc finish, low-carbon steel — for load distribution under the nut 4 × 3/8"-16 nylon-insert lock nuts, zinc finish, Grade 2 — vibration-resistant retention Which casters does this kit fit? Fits any plate-mount caster with a 3/8" bolt-hole diameter — typically: 2" wide casters with 4" × 4-1/2" top plates Standard-duty casters rated up to ~1,500 lb capacity per caster Standard industrial cart, material-handling, manufacturing, and warehouse applications For 4-1/2" × 6-1/4" or larger plates with 1/2" bolt holes, use our 1/2"-13 kit instead. For 1-1/4" wide casters with smaller plates, use our 5/16"-18 kit. Engineer Tip If you're mounting to thin-gauge steel (≤14 ga.), the thread-cutting screws self-tap and skip the need to drill clearance holes. For wood platforms or fabricated steel ≥1/8" thick, use the carriage bolts with a square hole punched or drilled to 3/8" — the square shoulder seats and prevents bolt rotation while you tighten the lock nut. Common Applications Industrial dollies, material-handling carts, and warehouse trucks Manufacturing line carts, fabrication shop bases, and assembly fixtures Plate-mount casters in 4-1/2" × 6-1/4" or smaller heavy-duty plate sizes Tool boxes, parts cabinets, and rolling work platforms Most 2" wide casters with 4" × 4-1/2" plates Frequently Asked Questions How many casters does one kit mount?One kit (16 pieces) mounts a single plate-mount caster. For a 64-piece set (mounts 4 casters) alternative, see our 64-piece set (mounts 4 casters). Will these bolts fit a different caster top plate size?This kit is sized for 3/8" bolt-hole diameter, which matches caster plates listed above. For other plate sizes, choose the 5/16", 3/8", or 1/2" kit that matches your bolt-hole diameter. Are these stainless?No — these are zinc-plated low-carbon steel. For washdown, food-grade, marine, or chemical environments, request stainless 304 or 316 hardware via our quote desk. What's the difference between the carriage bolts and the thread-cutting screws?Carriage bolts pass through a pre-drilled or punched 3/8" hole and secure with a nut and washer on the back side — best for wood or steel where you have access to both sides. Thread-cutting screws self-tap into thin steel and only need access from the caster side. The kit ships both so you can choose the right method per installation. Are these grade 5 or grade 8?The carriage bolts are ASTM A307 Grade A (commercial grade, ~60 ksi tensile). For higher-load critical applications, request Grade 5 or Grade 8 via the quote desk. Need stainless, Grade 5/8, or a custom thread spec? Our procurement team sources upgraded hardware for OEM, MRO, and aerospace builds. Same-day quote. Request a Custom Quote {"@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [{"@type": "Question", "name": "How many casters does one 3/8\" caster mounting hardware kit mount?", "acceptedAnswer": {"@type": "Answer", "text": "One 16-piece 3/8\"-16 caster mounting hardware kit mounts one plate-mount caster."}}, {"@type": "Question", "name": "Will 3/8\" caster bolts fit different plate sizes?", "acceptedAnswer": {"@type": "Answer", "text": "This 3/8\" kit fits caster top plates designed for 3/8\" bolt-hole diameters. For other plates, use the 5/16, 3/8, or 1/2 kit that matches your bolt-hole spec."}}, {"@type": "Question", "name": "Is 3/8\" caster mounting hardware stainless?", "acceptedAnswer": {"@type": "Answer", "text": "Standard 3/8\" caster mounting hardware is zinc-plated low-carbon steel. Stainless 304 or 316 hardware is available via custom quote for washdown, food-grade, or marine environments."}}, {"@type": "Question", "name": "What is the difference between caster carriage bolts and thread-cutting screws?", "acceptedAnswer": {"@type": "Answer", "text": "Carriage bolts pass through a pre-drilled hole and secure with a nut and washer on the back side, ideal for wood or fabricated steel with two-sided access. Thread-cutting screws self-tap into thin-gauge steel and require access from only the caster side."}}]}
