Monks of the Way of the Iron Grip focus on close combat, including grapples, locks, and pins, but also incorporate acrobatic leaps and spins into their martial arts.  These Monks work to inure themselves to pain utilizing their training and Ki to reinforce their bodies against all harm.

Skin of Iron

The Monk trains for years, hardening his body against the elements and weapons. At 3rd level,  the Monk gains an Armor Class of 16 if it would be lower.  Dexterity and wisdom bonuses do not add to this AC, nor do shields.  Magical bonuses and spells that increase armor class do apply, however.  The AC increases by 1 at 7th level, and again at 11th level and 17th level. After a long rest, the monk gains temporary hit points equal to the roll of his martial arts die plus strength modifier.  These temporary hit points remain until depleted or until the monk takes a long or short rest.   

Trained Grappler

At 3rd level, the Monk gains proficiency in the Athletics skill.  If already proficient, he gains expertise in this skill.  Additionally, when you use your flurry of blows feature, you can replace any or all the attacks granted with grappling attempts.

Earth Stance

At 6th level, the Monk does not gain disadvantage, nor do enemies gain advantage against him when he is prone. If the monk does not move at all during his turn, he can spend a Ki point as a reaction to reduce any forced movement effect on him to 0 .  He also cannot be knocked prone unless he wishes to during this time.  This stance lasts until the beginning of his next turn or until the monk moves. 

 

Coils of Iron

At 11th level, a target grappled by the monk takes damage equal to his strength modifier each round at the beginning of the monk's turn.  If the monk is the target of an individual attack from another creature while grappling a target, he may spend 3 Ki points to redirect the attack against the creature he has grappled as a reaction.  The monk can use this ability after the attack roll is known but before damage is rolled for the attack.

Meditation of the Iron God

At 17th level, by spending 6 Ki Points and a bonus action, the monk becomes a living fortress.  For the next minute, he may reduce incoming damage from any source by an amount equal to the roll of his martial arts die.  The die is rolled separately for each instance of damage.  During this time, the monk must continue to spend his bonus action each round to maintain this ability and his movement rate is reduced by half.  If the monk reduces the incoming damage to 0 in this manner, he suffers no additional effects that may be caused by the attack in question (ex: stunning, additional poison, forced movement, being knocked prone, etc.).