J Bolts
- Hook Firm, Anchor Concrete Steadily.
- Factory J Bolts, No Loose Failure.
- Durable Anchor, Fit All Foundations.
Sinsun J Bolts Factory | Stainless Steel & Galvanized J Bolts for Concrete
Sinsun is a professional J bolts factory and reliable global top supplier. We manufacture premium stainless steel J bolts, galvanized J bolts, M10 J bolts and foundation J bolts for concrete anchoring. Get custom J shaped anchor bolts with stable load capacity for construction & industrial projects.
Get a Quick QouteJ Bolts Factory – Sinsun Top Fastener Supplier & Manufacturing Partner for J-Type Hook Anchor Bolts
Direct J bolts factory with hot‑dip galvanising and stainless steel options. Partner with a leading fastener supplier for foundation J bolts, M10 J bolts, and custom J‑shaped anchor bolts. Get factory pricing & fast lead times.
product overview : what is a j bolt?
J bolts, also known as J-shaped anchor bolts or hook J bolts, are specialised fasteners with a distinct J-shaped hook end and a fully threaded shank. Known as boulons en J in European industry and pernos en J in the Latin American markets. These anchor fasteners embed firmly into concrete, masonry and foundation structures to provide permanent and stable anchoring support. M10 J bolts, 3/4 J bolts for concrete are common mainstream specifications, ranked as top choices for residential, commercial and industrial foundation installation.
Sinsun is a professional J bolts manufacturer, providing differentiated product quality than generic suppliers. And the majority of factories can only offer standard size finished goods with a single surface treatment. We control independently the selection of raw materials, the precision of hook bending and the machining of threads to suit a variety of complex working conditions. All our steel J bolts are constructed according to international construction standards, with a uniform thread pitch and integrated hook structure to avoid pull-out.
Low-cost J anchor bolts often have problems such as hook deformation, thread slipping and poor corrosion resistance. We solve these critical industry pain points with integral forging and precise heat treatment. Our stainless steel J bolts and galvanised J bolts possess high structural stability against long-term static loads and outdoor exposure. We also supply five sets of J bolts and nuts that are perfectly matched to support one-stop procurement and simplify on-site bolt installation procedures.
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Foundation J Bolts
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Stainless Steel J Bolts
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Galvanized J Bolts
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Heavy-Duty Hook J Bolts
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Carbon Steel J Bolts (Plain Finish)
Send inquiry Now| Thread Size | Rod Diameter (mm) | Length Range (mm) | Thread Length (mm) | Hook Inside Diameter (mm) | Grade | Finish |
| M6 | 6 | 40 – 120 | 20 – 60 | 12 – 20 | 8.8 | Zinc / HDG / Plain |
| M8 | 8 | 50 – 150 | 25 – 70 | 16 – 25 | 8.8 | Zinc / HDG / Plain |
| M10 | 10 | 60 – 200 | 30 – 100 | 20 – 32 | 8.8 / 10.9 | Zinc / HDG / SS304 |
| M12 | 12 | 70 – 250 | 35 – 120 | 25 – 38 | 8.8 / 10.9 | Zinc / HDG / SS316 |
| M16 | 16 | 80 – 350 | 40 – 150 | 32 – 50 | 8.8 / 10.9 | HDG / SS304 / SS316 |
| M20 | 20 | 100 – 450 | 50 – 200 | 40 – 65 | 8.8 / 10.9 | HDG / SS316 |
| M24 | 24 | 120 – 500 | 60 – 250 | 50 – 80 | 8.8 / 10.9 | HDG |
| M30 | 30 | 150 – 600 | 80 – 300 | 65 – 100 | 8.8 / 10.9 | HDG |
| M36 | 36 | 180 – 700 | 100 – 350 | 80 – 120 | 8.8 / 10.9 | HDG |
| M42 – M64 | 42 – 64 | 200 – 800 | 120 – 400 | 100 – 160 | 8.8 / 10.9 | HDG (Custom) |
| Parameter | Specification |
| Standards | DIN 3570, ASTM A307, ASTM A36, ASME B18.31.5, ISO 9001:2015 |
| Materials | Carbon steel (Q235, C1022, 10B21, 35K, 45K), stainless steel (SS304 / SS316 / A2‑70 / A4‑80), alloy steel (40Cr, 35CrMo, SCM435) |
| Strength Grades | 4.6, 4.8, 5.6, 8.8, 10.9, 12.9 (metric) / Grade 2, Grade 5, Grade 8 (imperial) / A2‑70, A4‑70, A4‑80 (stainless) |
| Thread Type | Metric coarse & fine; UNC / UNF inch threads; BSW upon request |
| Surface Finish | Hot‑dip galvanised (ASTM A153, 45‑85 µm), electro‑zinc plated (ASTM B633), black oxide, black phosphate, plain, Dacromet (zinc flake), powder coating |
| Leg Length (L) | 40 mm – 800 mm (1.5" – 32") custom |
| Thread Length (T) | 20 mm – 400 mm (0.8" – 16") custom |
| Hook Inside Diameter (C) | 12 mm – 160 mm (0.5" – 6.3") custom |
| Rod Diameter | M6 – M64 (metric) / ¼" – 2½" (imperial) |
| Thread Tolerance | 6g (plain finish), 6h (plated finish) |
| Tensile Strength (Class 8.8) | ≥800 MPa |
| Yield Strength (Class 8.8) | ≥640 MPa |
| Tensile Strength (A4‑80) | ≥800 MPa |
| Rolled Threads | Yes – standard on all orders (superior fatigue resistance and torque transfer) |
J Bolts for Concrete
J bolts for concrete are the most significant embedded fasteners for building and wall foundation construction. The unique J-hook structure is firmly locked in concrete to ensure strong pull-out resistance and stable anchoring force. Foundation J bolts Fix steel frames, wall supports and foundation bases without displacement. The bolts guarantee the building's overall structural stability and its safety.
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Industrial Mechanical Equipment Fixing
Large mechanical equipment bases and production line supports are attached to concrete floors with heavy-duty hook J bolts. They resist impact and vibration forces generated during continuous operation of equipment. High strength steel “J” bolts prevent loosening and deformation under long-term dynamic loads. They reduce equipment operation deviation and extend mechanical service life.
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Outdoor & Municipal Engineering Construction
Galvanized J bolts are used for street facility foundation fixing, guardrail bases and outdoor municipal facilities. The zinc coating protects against wind and rain erosion. These anchor bolts are stable in long-time outdoor exposure environments. They are widely employed in urban renovation and road auxiliary engineering.
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Marine & Humid Environment Projects
Stainless steel J bolts are suitable for coastal docks, offshore auxiliary facilities and humid industrial workshops. They resist salt fog and high humidity corrosion that quickly destroys ordinary carbon steel bolts. High anti-oxidation performance, reduces later maintenance and replacement frequency. The bolts are for long-term stable anchoring in marine foundation facilities.
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Pipeline & Electrical Suspension Installation
Hanger J bolts are used for securing the suspension of water pipes, ventilation ducts and electrical wiring systems. Flexible hook structure can be adjusted to different pipe diameters and suspension heights. Convenient construction and neat overall layout by installing J-bolts. These bolts provide safe and stable suspension operation for different pipeline systems.
READ MOREWhy Choose Sinsun J Bolts?
Factory Direct Pricing, No Middlemen
We have the production line.” No dealers. No middlemen. No secret markups. You pay factory prices. End of story. This means a saving of 25-40% compared to buying through trading companies.
Quality Control, In-House from Beginning to End
Incoming raw material → Cold bending → Thread rolling → Heat treatment → Surface finishing → Final inspection We do each step under our own roof. We do not outsource critical processes, so you always get consistent quality.
Traceability & Certification End-to-End
Material certs EN 10204 3.1 needed? Done. Third party inspection reports? We have those. We offer complete documentation for every batch of J bolts, from melt origin to thread gauging.
Custom Bending – No MOQ
Not working with standard sizes? How long your legs are. How long your hook is. How long the thread is. We custom make J bolts for any quantity order from 10 pieces to 100,000 pieces.
Post galvanising thread chasing
This sounds small but saves huge headaches. After hotdip galvanising we run a thread chaser through every nut and over every bolt leg. Nuts turn by hand. No hammering. No cross-threading. No time wasted on installation.
We ship worldwide to more than 50 countries
We ship J bolts to construction sites and industrial plants in Europe (Germany, France, UK, Poland), South America (Brazil, Chile, Argentina), Australia, the Middle East (UAE, Saudi Arabia), Southeast Asia (Indonesia, Vietnam, Philippines), and Africa (South Africa, Nigeria).
Customer Projects & Feedback
It is our quality team's policy not to compromise on German standards. Sinsun provided us with grade 8.8 J bolts that are fully certified to EN 10204 3.1.In the lab we ran tensile strength, yield strength and thread gauge tests – all passed. All 5,000 pieces in the batch had a consistent black oxide finish. "We now list Shinsun as an approved supplier of anchor bolts for our industrial building projects."
We required M16 hot dipped galvanised J bolts for a pre-engineered building warehouse. Our local distributor quoted us 45 days lead time and high prices. Sinsun: 28 days lead time. 30% cost down. The galvanising was even and the threads were clean, with no lumps of zinc to grind off. They helped us verify torque values for specific base plate thicknesses as well.Very professional.
"Solar farm mounting requires hundreds of J bolts per megawatt. We had three suppliers before we came to Sinsun. It was not necessary to grind or re-drill our rail profiles to fit stainless steel 304 J bolts. Delivery was done in 25 days instead of 30 days promised. The material certs for A2-70 were a perfect fit. “Would recommend to any contractor doing outdoor solar installation work.”
"Our mining equipment anchoring demands Grade 10.9 J bolts. Sinsun supplied them with full hardness test reports (32 HRC average). The hooks were bent precisely, and the leg lengths matched our drawing within ±1 mm. We also appreciated that they packed the J bolts in wooden crates with internal foam padding – no thread damage during the long sea freight to Durban port."
HOT FAQS
Q
What is the difference between J bolts and L bolts?
A: J bolts are bent 180 degrees at the embedded end (hook shape). L bolts bent at 1 90° angle. J bolts have better pull‑out resistance than L bolts because of the curved end which provides more concrete interlock.
Q
Are J bolts reusable after they are removed from concrete?
A: We do not recommend reusing J bolts The first tightening stretches the threads a little and deforms the hook in the concrete embedment. Reusing J bolts decreases pull-out resistance and creates safety concerns. Never reuse J bolts on a new pour.
Q
What size J bolt do I need for my concrete slab?
A: Building code is usually a minimum ½" diameter and embedment depth of 7" into concrete. Spacing is generally a maximum of 6 ft on centre with one bolt within 12" of each wall end. We can assist you in determining the appropriate size for your local seismic zone and wind loading requirements.
Q
How much torque should I put on J bolt nuts?
A. Correct torque is a function of diameter, grade, lubrication condition and depth of embedment. We will send you a torque chart with your order. General rule: tighten in a crisscross fashion rather than fully one nut at a time - this helps to ensure that the preload is even across the whole base plate.
Q
Do you sell J bolts that have nuts and washers already on them?
A: Yes, we can pack J bolts with matching nuts, flat washers and spring washers in the same carton. Some clients request nylon‐insert locknuts for high‐vibration applications. Tell us what you need and we will pre-assemble it before shipping.
Q
How to Measure J Bolts Properly？
A. The J bolt measurements are: rod diameter x overall length of leg (top of thread to bottom of hook) x inside diameter of hook (C dimension) x length of thread. Always refer to the product spec sheet, the order of the measurements may vary from manufacturer to manufacturer.
Q
How far in concrete do J bolts have to be embedded?
A: Smooth round anchor bolts usually have a standard buried depth of 25 times the diameter, with a 90 degree hook at the bottom. In seismic or high wind areas local building codes may require deeper embedment and larger square washers. We can make embedment recommendations based on your project’s load requirements.
Q
How do I install J bolts correctly in concrete forms?
A. According to the design drawing, mark the position of the steel bar and fix it with a template. Insert the J bolt and make sure it is vertical and not crooked before pouring concrete. The J bolt must be long enough to comply with your project depth guidelines, usually 1¾ to 2 inches from the inside edge of the form.
Q
What is your lead time for a 20 foot container of J bolts?
A: Standard lead time is 20-30 days after order confirmation, based on surface finish and grade. Hot dip galvanised orders may take an extra 5-7 days for the process of dipping and thread chasing. We offer expedited service for repeat customers.
Q
Can J bolts be installed after the concrete is cured?
A: Yes, you install cast-in-place J bolts before you pour. If you need to anchor after the concrete has cured, go for post-installed anchors such as expansion anchors, undercut anchors or adhesive anchors. J bolts are intended for cast in place.
Q
What grade is your carbon steel J bolts?
A: We manufacture J bolts to ASTM A307 (Grade A and B), ASTM A36 and customer specified grades. For metric applications we have available Grade 4.8, 8.8, 10.9 and 12.9. Full material certification available upon request.
Q
Do you sell J bolts with UNF (fine) threads?
A: Yes. Regular J bolts are UNC (coarse) threads. We can also make UNF (fine) threads if your application requires better vibration resistance or finer adjustment. Simply tell us your thread pitch.
| If your application is … | Choose this J bolt type |
| Standard concrete foundation indoor | Carbon steel, plain finish, Grade 4.8 |
| Outdoor structural anchoring (rain, sun) | Hot‑dip galvanised, Grade 8.8 |
| Marine dock, swimming pool, coastal area | Stainless steel 316 (A4‑80) |
| Food processing or chemical plant | Stainless steel 304 (A2‑70) |
| Heavy machinery or high‑load anchoring | Grade 10.9 or 12.9 hot‑dip galvanised |
| Solar panel mounting frame | Stainless steel 304 (A2‑70), zinc‑plated |
| Seismic zone or high‑wind area | Heavy‑duty J bolts (Grade 8.8+) with 3″ square washers |
| Automotive assembly or machine shop | Black oxide finish (non‑reflective, oil‑coated) |
| Temporary indoor concrete form | Plain carbon steel, Grade 4.6 (lowest cost) |
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