Mild Steel Tower Bolt ISI Price List in India (2025 Updated Guide)

Mild steel tower bolts are sliding door/gate bolts that lock by sliding a steel rod into a catch plate. They provide extra security when fitted on doors and windows. In India, ISI (BIS) standards apply – ferrous tower bolts must meet IS 204 (Part 1) specifications. Recent regulations (from Oct 2023) make ISI certification mandatory for all door fittings, including tower bolts This guide covers the 2025 price ranges, standard sizes, and top suppliers of ISI-marked mild steel tower bolts across India (especially in Delhi, UP, Punjab, etc.)

Tower bolts (a type of barrel bolt) typically consist of a cylindrical bolt that slides into a keep. When extended, the bolt enters a catch plate on the door frame and locks the door They come in various finishes (painted, chrome-plated, powder-coated) and materials (mild steel, brass, stainless). Mild steel is common for interior doors due to its strength and affordability, while brass or stainless variants resist corrosion better. All ISI-certified mild steel tower bolts conform to IS 204 (Part 1):1991, the BIS standard for ferrous (mild steel) tower bolts. Major hardware hubs (Delhi/NCR, Ghaziabad, Ludhiana, and Aligarh) host many manufacturers – for example, Crown Industries (Crown ISI brand) in Ghaziabad (UP) supplies ISI-marked tower bolts to Delhi.

What Is a Mild Steel Tower Bolt ISI?

A Mild Steel Tower Bolt ISI is a sliding lock made from mild steel and certified as per IS 204 (Part 1):1991, which is the Indian Standard for ferrous (mild steel) tower bolts.

It works using a sliding mechanism:

1. A cylindrical steel rod moves inside a barrel
2. When you slide it into the catch plate (keep), it locks the door
3. When you pull it back, the door opens

This simple mechanism makes it ideal for everyday security needs.

Why ISI Certification Is Important (Mandatory After Oct 2023)

The Government of India announced that from October 2023, all door fittings, including tower bolts, must carry the ISI mark.

Reasons why ISI matters:

• Guarantees quality & durability
• Ensures correct raw material strength
• Prevents cheap, weak, unsafe hardware from reaching homes
• Ensures accurate rod diameter, thickness and performance
• Improves home security and door life

If you're buying tower bolts in 2025, always look for the ISI logo + standard number (IS 204 Part 1).

How Tower Bolts Work (Simple Explanation)

Tower bolts (also called barrel bolts) have:

• A steel rod
• A barrel body
• A catch plate (keep)
• A sliding knob

When you slide the rod into the catch plate, the door is locked.When you pull the rod back, the door opens.

This mechanism is used on:

• Main doors
• Bedroom doors
• Bathroom doors
• Windows
• Almirahs & cupboards
• Gates
• Shutters

Materials & Finishes Used in Tower Bolts

Although tower bolts come in many materials, Mild Steel (MS) is the most popular in India due to:

• Strength
• Low cost
• Easy availability
• Smooth operation

Common Finishes Available:

• Black powder-coated
• Chrome plated
• Zinc plated
• Painted finish
• Matte finish

Black and powder-coated variants are trending in 2025 for modern interiors.

Common Uses of Mild Steel Tower Bolts

People use MS tower bolts in places where a simple, strong slide-lock is needed:

Homes

• For bedrooms & bathrooms
• For windows
• For small cabinets
• For almirahs (jewellery, important documents)

Offices

• To secure office cabinets
• To lock storerooms
• To secure internal rooms

Garages

• To protect vehicles, bicycles, tools, and storage units

Shops

• For main shutters
• For stock room doors

Because they are cheap, durable, and simple, they are found almost everywhere in India.

ISI Standard for Mild Steel Tower Bolts (IS 204 Part 1)

All ISI-certified MS tower bolts follow:

• Standard: IS 204 (Part 1): 1991
• Material: Ferrous (Mild Steel)
• Rod Diameter: 10 mm (standard)
• Lengths Available: 100 mm – 300 mm
• Test Requirements: Tensile strength, Rust resistance, Smooth sliding movement, Coating durability, Impact resistance

Price List: Mild Steel Tower Bolt ISI (2025 Updated)

Below are the latest 2025 market prices based on current listings, wholesale markets (Delhi, Ghaziabad, and Ludhiana) and B2B data:

Examples from recent listings:

• 4–6 inch: ~₹20
• 5 inch (Pack of 12): ₹140 (≈₹12 each)
• 8 inch (Standard): ~₹128
• 8 inch Black Powder-Coated (MS): ~₹22

Prices vary depending on:

• Brand
• Thickness
• Finishing
• Packaging
• City (Delhi cheaper, South India slightly higher)

ALSO READ: 5 types of tower bolts and their uses

Top Indian Markets for Mild Steel Tower Bolts (2025)

1. Delhi NCR 

• Largest supplier hub
• Home to many ISI-certified brands
• Preferred by contractors & builders

2. Ghaziabad (UP)

• Known for quality hardware
• Home of CROWNISI
• Supplies Delhi, Noida, Haryana & UP

3. Ludhiana (Punjab) : Large-scale fastener & hardware manufacturing
4. Aligarh (UP) : Traditional hardware manufacturing region
5. Mumbai: Sells large volumes of MS hardware & fittings

Why Choose CROWNISI for ISI Mild Steel Tower Bolts?

CROWNISI, based in Ghaziabad (Delhi NCR), is a trusted brand supplying ISI-certified mild steel tower bolts across India.

• ISI-Certified (Mandatory Standard): Complies with IS 204 Part 1.
• Strong Mild Steel Rods: Standard 10 mm diameter for maximum strength.
• Smooth Sliding Mechanism: No friction, no shaking, long-lasting performance.
• Available in All Sizes (100 mm to 300 mm): Perfect for homes, shops, offices, and industrial use.
• Rust-Proof Coating: Zinc, chrome, or powder-coated finishing.
• Best Wholesale Rates: Especially beneficial for dealers, hardware shop owners and contractors.
• Pan-India Supply: Delhi, UP, Punjab, Haryana, MP, Rajasthan, and more.

Where to Buy ISI Tower Bolts in India?

You can purchase ISI-certified tower bolts from:

• Local hardware shops
• Wholesale markets in Delhi, Ghaziabad, Ludhiana
• Online marketplaces (IndiaMART, TradeIndia, etc.)
• Direct manufacturers like CROWNISI

Always check:

• ISI mark
• Model number
• Brand credibility
• Rod thickness
• Finishing quality

FAQs

1. What is a tower bolt and how does it work?

A tower bolt (barrel bolt) is a sliding lock that secures doors or gates. The steel rod slides into a catch plate and locks the door. Used in wooden doors, windows, gates, and shutters.

2. Which Indian Standard covers mild steel tower bolts?

IS 204 (Part 1):1991 is the BIS standard for mild steel (ferrous) tower bolts.

3. Is ISI certification mandatory for tower bolts?

Yes. From October 2023, all door fittings—including tower bolts—must be ISI-certified.

4. What are the common sizes for mild steel tower bolts?

Standard lengths: 100mm, 150mm, 200mm, 250mm, 300mm.

5. Where can I buy ISI-certified tower bolts in India?

Major markets include Delhi, Ghaziabad, Ludhiana, Aligarh, and online platforms. CROWNISI (Ghaziabad) is a trusted manufacturer.

Final Conclusion

Mild Steel Tower Bolts are essential for home, shop, and office security due to their strength, affordability, and simple locking mechanism.
With ISI certification now mandatory, buyers can trust the quality and safety of the hardware they purchase.

The 2025 price list shows that ISI-marked MS tower bolts are still very affordable, making them one of the best-value security fittings in India.
If you want premium-quality ISI tower bolts, CROWNISI is one of the leading manufacturers in Delhi/NCR trusted by wholesalers, retailers, and builders.