How to Read a Hard Hat Expiration Date
Most hard hats have no printed expiration date. Instead, a date code is molded into the shell, usually on the underside of the brim or inside the crown. Read it as the month and year the shell was made, then check your maker's guidance for how long the hat and its suspension may stay in service.
LIFT Safety HDF-24CWGBest overall
MSA 475407Light hot-work full brim
AFP HHA4754Lightest of the top fiveWhere to find the date code
Take the hat off and turn it over. Look at the underside of the brim first, then at the inside of the crown. The code is molded into the plastic, so you are looking for raised or recessed marks rather than a printed sticker.
Good light helps. Tilt the shell so the light hits the marks at an angle, and the numbers will stand out. Wipe off dust or grime with a damp cloth if the marks look faint.
- Underside of the brim, which is where MSA says it molds the code on its Skullgard hats
- Inside the crown, near the top of the shell
- Near the ANSI label or other molded text, which often sits in the same area
How to read the clock-style dial
The most common format looks like a small clock face. A circle holds the numbers 1 through 12 around its edge, with a two-digit year in the center. An arrow points to one of the numbers.
The arrow shows the month. The center number shows the year. So an arrow pointing at 7 with 25 in the middle means July 2025.
Some dials also include a dot or a number for the day. If you see extra marks, check the maker's technical sheet for that model, since the layout can vary between brands.
Other date code formats
Not every hat uses a dial. Some makers mold a plain month and year, and others use a short code that only the maker's guide explains. When in doubt, look up the brand and model, or contact the manufacturer with the model number and the code you see.
The table below shows common layouts and how to read them.
| Format | What you see | How to read it |
|---|---|---|
| Clock dial | Circle with 1 to 12, arrow, two-digit year | Arrow points to the month, center is the year |
| Month and year | Two numbers such as 07/25 | Month first, then year, unless the maker says otherwise |
| Day, month and year | Three groups of numbers or a dial with a day marker | Follow the maker's technical bulletin for the order |
| Short code | Letters and numbers with no clear date | Look up the model or ask the maker |
Manufacture date is not service life
The code tells you when the shell was molded. It does not tell you when you started wearing it. The MSA Skullgard listing makes this point directly: the date codes are molded under the brim with the year and month of manufacture, and the date does not indicate service life, which begins when the helmet is placed into service.
That matters if a hat sat in a storeroom before you got it. Many makers and safety programs suggest replacing shells a set number of years after manufacture or after first use, and they often suggest replacing the suspension more often than the shell. The exact numbers differ by brand, material and site policy, so use the instructions that came with your hat.
Our comparison data does not list a replacement interval for any hat, so we do not give one here. Your employer's safety program, if you have one, may set a stricter limit than the maker does.
Replace a hat sooner when you see damage
A hat that is within its dates can still be unfit to wear. Any hat that has taken a hard hit should come out of service, even if it looks fine. The shell can have damage you cannot see.
Check the shell and suspension before each shift. Flex the shell gently with both hands and look for problems.
- Cracks, dents, gouges or deep scratches in the shell
- Chalky, faded, sticky or brittle plastic
- Frayed, torn or stiff suspension straps
- A ratchet that slips or will not hold its setting
- Signs of heat or chemical damage, such as warping or discoloration
- A missing or unreadable date code or ANSI label
Safety notes
Do not drill, cut or paint the shell, and do not apply solvents or adhesive labels unless the maker allows it. These can weaken the plastic or hide damage. Stickers and paint can also cover the date code.
Electrical class matters here too. A Class G hat is rated for general use and a Class E hat for higher voltage work, while Class C offers no electrical protection. A cracked or damaged shell can no longer be trusted to give the protection its label claims, so retire it before working near live conductors.
If you work at heights, make sure the hat has a chin strap if your site requires one, and replace the hat after any fall impact.
Check dates when you buy
Look at the date code on a new hat before you rely on it, since stock can sit for a while. If the code shows the shell was made some time ago, ask the seller or maker how that affects its usable life. The standard edition on the label is worth a glance too. For example, the MSA Skullgard listings cite ANSI/ISEA Z89.1-2014, while one Ridgeline full brim hat is listed to the older Z89.1-2009.
If you are shopping, our best hard hat page puts certification, shell material, weight and heat rating side by side, so you can match a hat to your trade. Read it alongside the maker's service-life guidance, since specs alone do not tell you how long a hat should stay in use.
You can also use that comparison to plan replacements. Hats with replaceable suspensions, such as the Ridgeline models that list replaceable brow pads and headbands, let you swap worn parts. The shell still follows its own date rules, so keep track of both. For a fuller look at what the labels mean, see the buying guide on our hard hat comparison.
Frequently asked questions
Can I still wear a hat with no visible date code?
It is safest not to. Without a date you cannot tell how old the shell is. Contact the maker with the model number, or replace the hat.
Does the suspension have its own date?
Often it does. Many suspensions carry their own mark, and makers commonly advise replacing them more often than the shell. Check the maker's instructions.
Does a sticker or paint void the date?
No, but it can hide the code and may harm the shell. Ask the maker before applying anything, and keep the code readable.
Do the numbers on the dial mean days?
Usually the arrow points to the month and the center number is the year. Some formats add a day mark, so check the maker's bulletin for your model.