Breakpoints: (*some values assume optional feats/skills were chosen as above) {}=values w/ Defensive Stance active
@13: Dwarven Defender 3/Monk 10 -> Str 16{20} Dex 14 Con 19{23} Int 10 Wis 14 Cha 6 > D16 L16 Lo* 13 T13 >> AC 18{22} BAB 10 Fort 15{17} Refl 11{13} Will 13{15} HP 99-181{125-207} unarmed strike (+14/+11/+8/+5 {+16/+13/+10/+7} | dmg 4-13{6-15} threat 19-20/x2 crit 8-26{12-30})
@20: Dwarven Defender 10/Monk 10 -> Str 16{20} Dex 14 Con 21{25} Int 10 Wis 14 Cha 6 > D23 L23 Lo* 13 T13 >> AC 18{22} BAB 17 Fort 20{22} Refl 13{15} Will 17{19} HP 161-320{201-360} unarmed strike (+21/+18/+15/+12/+9/+6 {+23/+20/+17/+14/+11/+8} | dmg 4-13{6-15} threat 19-20/x2 crit 8-26{12-30}) DR 6/-
@27: Dwarven Defender 14/Monk 13 -> Str 16{20} Dex 14 Con 22{26} Int 10 Wis 14 Cha 6 > D27 L27 Lo* 13 T25 >> AC 23{27} BAB 21 Fort 24{26} Refl 16{18} Will 20{22} HP 237-461{291-515} unarmed strike (+25/+22/+19/+16/+13/+10 {+27/+24/+21/+18/+15/+12} | dmg 4-15{6-17} threat 19-20/x2 crit 8-30{12-34}) DR 18/- SR 23
Fin: Dwarven Defender 22/Monk 18 -> Str 16{20} Dex 14 Con 26{30} Int 10 Wis 14 Cha 6 > D40 L35 Lo* 13 T40 >> AC 27{31} BAB 27 Fort 33{35} Refl 23{25} Will 27{29} HP 501-848{581-928} unarmed strike (+34/+31/+28/+25/+22/+19 {+36/+33/+30/+27/+24/+21} | dmg 4-23{6-25} threat 19-20/x2 crit 8-46{12-50}) DR 24/- SR 28
***
This guy lacks punch compared to his Hammer Fist brothers, but he can take abuse. And lots of it.
As are all my builds, this build is designed for fun play from level 1--it should be playable and enjoyable at all stages of the single-player OCs and dwarven-monk-friendly modules. Some folks would take a full 30 levels of dwarven defender for maximum DR, but I chose to sacrifice 8 levels (6 DR) in favour of monkly goodness like Diamond Soul and Empty Body (and 1d20 fists!).
Don't forget to make use of Defensive Stance--it helps bring the Hammer Wall closer to his Hammer Fist brethren in the early levels, and never hurts. While it's meant for defense, in this build a key benefit is simply the +2 AB and +2 damage from the boosted strength.