Fitting a hard hat properly: suspension, clearance and the sweatband

Most hard hats in use are fitted badly, and the most common fault is the one that matters most: the suspension set too high, so the shell sits directly on the skull.

The clearance is the safety feature

A hard hat works by deforming. The shell spreads the force of an impact and the suspension stretches to absorb it, and both of those require space between the shell and your head — roughly an inch and a quarter.

Set the suspension so the shell rests on your head and that gap disappears. At that point the helmet is a hat.

Check it by pressing down on the top of the shell while wearing it. You should feel the shell move down and stop before touching your head. If it touches immediately, lower the suspension.

Four adjustments, in this order

1. Crown height. Most suspensions have three or four positions where the straps attach. Set this first — it controls the clearance. Lower position, more clearance, helmet sits lower on the head.
2. Headband circumference. Ratchet at the back. Snug enough that a firm shake of the head does not move it; loose enough that there is no pressure point after an hour.
3. Nape strap angle. The rear strap should sit below the occipital bump, not on it. This stops the helmet tipping forward.
4. Front-to-back tilt. The brim should be roughly level. Tipped back exposes the forehead; tipped forward blocks your upward view, which matters when the hazard is above you.

The shake test

Put it on, fasten nothing else, and shake your head firmly side to side and then nod hard. The helmet should stay put. If it slides, tighten the ratchet a click. If your scalp aches after twenty minutes, it is a click too tight.

Chin straps

Not required for most general construction, and essential for work at height, in wind, or where you bend forward often. A helmet that falls off at the moment you lean into something is no protection at all.

If you use one, it should be a four-point strap for work at height. Two-point straps are for keeping the helmet on your head in wind, not for a fall.

The sweatband

The most-neglected component. It sits against your forehead all day, absorbs sweat, and becomes a source of skin irritation and a bacterial problem within weeks.

• Wash it weekly with mild soap, air dry.
• Replace it every few months, or immediately if it has hardened.
• Wicking replacements are inexpensive and noticeably more comfortable than the standard foam.

Glasses, ear defenders and hoods

Anything else worn on the head changes the fit. Safety glasses arms under the suspension straps lift the helmet; ear defender headbands can push it forward. Fit the helmet with everything else you actually wear, not on its own.

Where you use several together, slotted helmets that accept clip-in ear defenders and visors solve the problem properly, because everything is mounted to the shell rather than fighting it.

Hair and headwear

Long hair tied at the nape can push the helmet forward — tie it low or to the side. Winter liners and skull caps must be thin enough to preserve clearance. Baseball caps worn under a hard hat, brim forward, are a common site rule violation because the peak stops the suspension seating.

Two minutes at the counter

Bring the glasses and defenders you wear and we will fit the helmet with them on, adjust the four points and show you the clearance test. Most people leave wearing it a full position lower than they arrived, and say it is more comfortable that way.

Replacement suspensions

The suspension is a consumable and it is sold separately by most manufacturers. Replacing one takes about two minutes: the straps unclip from four or six keyed slots in the shell and the new one clips in the same way.

Two things to check when fitting a new one. The straps must be seated fully into their slots, which usually requires a firm push until they click. And the crown height position must be reset — a new suspension arrives at a default that is rarely where you had the old one.

Reverse wear

Some helmets are certified for wearing backwards, which matters for anyone using a welding hood or working in a confined space where a brim is in the way. It is marked on the shell or the suspension, usually with a small reverse arrow.

If the marking is not there, the helmet is not certified for it, and wearing it backwards changes both the coverage and the way the suspension distributes an impact.

Chin straps and work at height

Where a fall is possible, a chin strap turns a helmet from something that comes off on the way down into something that is still there at the bottom. Four-point straps are the ones designed for this; a two-point strap is a wind retainer.

Adjust it so it is snug under the chin with room for one finger. A loose strap does nothing and an over-tight one is the reason people unclip it.

Glasses that fit under a helmet

Safety glasses with thin, flat arms sit under a suspension without lifting it. Wraparound sports-style arms are thicker and frequently do lift the helmet, which quietly removes the clearance you spent time setting. If you wear glasses all day, bring them when you buy the helmet.