What is the Carhartt B01?
The B01 is the Duck Double Front Work Dungaree — the original Carhartt double knee. It is a straight-cut work pant in firm 12 oz duck canvas with a second layer of fabric sewn over the front of the leg from mid-thigh to below the knee, a hammer loop on the left leg, a ruler pocket on the right and multiple utility pockets. It is the most iconic Carhartt pant and the one most people mean by 'Carhartt double knee'.
What does the double knee actually do?
It doubles the fabric where trades kneel on concrete. The second layer is open at the bottom, which lets a knee pad slide in. On vintage pairs the outer layer often fades faster than the inner, giving the two-tone look collectors like. The double front also makes the pant hang straighter and heavier through the leg.
How does the B01 fit?
Straight and roomy through the thigh with a slight taper to the hem, sitting at the natural waist. Vintage pairs were cut for work boots, so the leg opening is wide. Because duck canvas shrinks in the wash, a tagged 34 waist often measures 33 or less — always go by flat measurements.
What is the difference between B01 and B136?
B01 is unwashed firm duck — stiff when new, breaking in over months. B136 is the Washed Duck Double Front, pre-washed so it is softer and slightly more faded from the first wear. Same cut, same double knee. Vintage B01s that have been broken in by years of work are the most prized because the fade has real history.
What should I check on a vintage double knee?
The knee layers — check they are both intact and look at the open hem of the outer layer for fraying. The hammer loop is often torn off. Check the crotch seam and the back pocket corners for blow-outs, and the waistband for stretching. Most of these are repairable, and a visible knee repair is part of the reworked look.
How do you rework a double knee?
Common jobs are re-setting the knee layers, tapering the leg, re-hemming to a cropped length, and replacing a blown-out back pocket with a panel from a second pair in a contrasting fade. We keep the hammer loop and ruler pocket wherever possible because they are part of the identity.
Which colours sell best?
Carhartt brown and black are the fastest, followed by moss and the faded tan that brown becomes with years of wear. Grey and dark navy are scarcer and sell to buyers who want the silhouette without the obvious workwear colour.
Every piece we sell is reworked by these standards
Everything written here comes from grading and reworking Carhartt every day. Browse what's in now, or message us and we'll send photos and measurements of anything.