Stainless Steel L Bolt

Choosing the Right L-Bolt (Anchor “L” Bolt)

What is an L-bolt & when to use it?

An L-bolt (L-type anchor bolt) is a bent rod with threads on one end and an “L” hook on the other, usually cast into concrete.

Use an L-bolt when you need a fixed anchor point in concrete to hold down:

Base plates & structural columns

Machinery, skid bases, equipment frames

Poles, masts, sign boards, handrails, pipe supports

The hooked leg is embedded in concrete; the threaded leg sticks out and takes nuts & washers to clamp the base plate.

Environment & corrosion – material & finish

Depending on the exposure, choose:

Standard carbon steel (plain / zinc / HDG)

For dry indoor or moderate outdoor environments (depending on coating).

Very common for civil/structural work: hot-dip galvanized (HDG) L-bolts for general outdoor foundations.

A2 (304) stainless L-bolt

For indoor/outdoor environments where corrosion must be controlled, but not fully marine.

Example: food plant interiors, plant rooms, light chemical exposure.

A4 (316) stainless L-bolt

For marine, coastal, chemical, or chloride-rich conditions.

Example: jetties, seafront structures, water treatment, chemical plants, poolside.

Rule of thumb:

General building / structural with concrete → HDG carbon steel

Stainless base plates, clean areas, or high corrosion → A2 or A4 stainless

Strong chlorides / marine / chemicals → A4 (316)

Match nuts & washers with the same material/finish (HDG with HDG, A2 with A2, A4 with A4).

Diameter & load level

Choose bolt diameter (M10, M12, M16, M20, M24, etc.) based on:

Tension loads (uplift, overturning, wind, seismic)

Shear loads (horizontal forces at the base)

Design standard / consultant requirements.

Larger diameter = higher steel strength and concrete breakout capacity, but the concrete design (embedment, edge distance, spacing) is equally important.

For light equipment & small poles → M10–M16
For columns, heavy equipment → M16–M24 and above (as per structural design)

Embedment depth & hook length – key to holding power

Two critical dimensions on the “L” side:

Embedment depth (hef) – vertical depth of the hook in concrete

Hook leg length – horizontal leg of the “L”

Together, these control:

Anchor pull-out resistance

Concrete breakout strength

Resistance to the bolt straightening under load

General idea (always follow design/standard):

Higher loads → greater embedment depth and longer hook.

Maintain adequate edge distance and spacing between bolts to avoid concrete splitting/breakout.

Incorrect embedment (too shallow) is one of the main reasons anchors pull out or crack concrete.

Mechanical Properties (Guide) – L-Bolts (Anchor “L” Bolts)

An L-bolt’s performance is governed by steel strength and concrete capacity.
Even if the steel is strong, failure can occur by concrete breakout, pull-out or bending if embedment is inadequate.

Stainless L-Bolts (A2 / A4)

A2-70 & A4-70

Material: A2 (304) or A4 (316) stainless

Property class: 70

Minimum tensile strength ≈ 700 MPa

Typical proof strength ≈ 450 MPa

Used with: A2-70 / A4-70 nuts and washers

Applications:

A2 L-bolts: General industrial, food plant interiors, clean environments, normal outdoor where stainless baseplates/equipment are used.

A4 L-bolts: Marine/coastal/chemical foundations, stainless structures, aggressive wash-down areas.

A4-80 (if used)

Material: High-strength A4 (316)

Property class: 80

Minimum tensile strength ≈ 800 MPa

Typical proof strength ≈ 600 MPa

For higher-load stainless anchorage where both strength and corrosion resistance are critical.