Most monastic traditions focus on dexterity as a pure expression, using it for speed and agility, wielding only light, fast weapons, or perhaps no weapons at all. Whilst a monk of the Way of the Weighted Steel still trains their dexterity and agility, they apply it in very different ways, to the point some don't even see them as a traditional monk any longer.

A monk of the Way of the Weighted Steel has studied the use of heavier weapons as a way to express their combat ability. They use practical knowledge of physics, such as leverage and centers of gravity, to ensure that their heavy instruments can be handled with minimal effort, and are able to spin and strike with them with ease, making these weapons seem a lot lighter than they actually are.

Weighted Instruments

You have trained to channel your technique through more unwieldy weapons than other monks. Starting with when you choose this tradition at 3rd level, you gain the proficiency with Greataxes, Greatclubs, Greatswords, and Mauls, and additionally these weapons count as monk weapons for you. 

Mastery of Balance

At 6th level, you have learned to observe other creatures stances and balance, and are able to exploit the weaknesses you observe. When a creature within 5 feet of you misses you with a melee attack roll, you may spend 1 ki point as a reaction to attempt to knock the creature off balance. It must succeed on a Strength saving throw against your ki save DC or be knocked prone. Starting at 11th level, whenever a creature fails this saving throw, its speed is reduced to 0 for the rest of the turn, as the wind is knocked out of its lungs from the sudden impact.

Fulcrum

Your training has emphasized the use of angles and rotations, as opposed to simple brute strength. Starting at 11th level, you gain a bonus to your Strength checks equal to your Wisdom modifier, and whenever you fail a strength check or strength saving throw, you may spend 1 ki point to reroll the check or saving throw, and must use the new roll. 

Steadfast Stance

Your training and use of heavy weapons requires a strong and heavy stance, and you are able to use the weight of your weapon to plant yourself in the ground. Starting at 11th level, you have advantage on Strength saving throws against effects that would knock you prone or move you against your will, and standing up when prone costs only 5 ft. of your movement. 

Weighted Soul

When you reach 17th level, the mastery you hold over balance, weight, and your and other creatures center of gravities is unparalleled. As an action on your turn, you can enter into a deep, unbreakable stance that completes all of your techniques. You gain the following benefits, which lasts until you move:

• You cannot be knocked prone or moved against your will
• You gain a +5 bonus to your AC
• Any heavy or two-handed weapon that you wield gains the thrown property, with a short range of 10ft and a long range of 30ft.
• You can replace an attack of opportunity with a use of your mastery of balance ability. You must still spend the ki points for this.