Iron Heart 14oz '20th Anniversary' Ultra-Heavy Classic Check Flannel Western Shirt (Sax Blue)

Back again! Here we have some of the best flannels!

To celebrate its 20th Anniversary, Iron Heart has re-released the very first flannel pattern that started it all!

At the time of its first release (20 years ago), this flannel fabric was constructed in 10oz cotton, the heaviest weight flannel that could be made at the time. Since then Iron Heart has only gotten better and better and has produced this latest version in an ultra-heavyweight 12oz Aspero cotton! The flannel fabric is slowly woven using vintage machines with thread-dyed colourways. The pattern is sharp and textured, unlike brands that use cheaper printing methods. This shirt is overdyed in pale grey bringing the total weight to 14oz!

For durability, this shirt is skillfully-constructed using vintage machines and features western-style front and back yokes. With black snaps, this is a classic yet modernised western look.

If you are looking for the GOLD-STANDARD in Japanese flannel Western shirts this is it!

  • 100% Cotton
  • Japanese 14oz ultra heavy flannel
  • Colours are thread dyed then over-dyed with pale grey
  • Twin chest pockets
  • Snap buttons
  • Brushed interior
  • Once washed (minimal shrinkage)
  • Slim fit
  • Made In Japan

Related Items

How We Measure

Pants and Shorts


With the major buttoned up open the jeans and lay them flat like shown. Measure from the front where the major button closes to the back belt loop. Then double this measurement to achieve the waist measurement.

The way we measure is different from 'Side to Side', If you are not used to our method you should downsize by 1 inch.

For example, side to side measurement for The Flat Head 3002 waist is 28inch and using our method 29.25 inch.

Front Rise:

With the jeans lying flat measure from the crotch bar tack to the top of the waistband. 

Back Rise:

Spread out the crotch so the bar tack is visible, then measure from the crotch to the top of the waistband.


One inch down from the crotch measure flat across to the other side.


Flatten the leg and measure along the inseam from the crotch to the leg hem. 

Leg Openning:

Measure straight across the hem from side to side.



Lay flat then measure from the shoulder's edge to the other shoulder's edge.


Lay shirt flat and measure from pit to pit.

Sleeve length:

With the sleeve flat measure from the shoulder to the cuff.

Arm hole openning:

Measure from the shoulder down to the pitt.

Vertical length:

With the shirt facing down, Measure from below the collar to the bottom hem.