Last time around the Titleist 716 T-MB iron was portrayed as a long iron hybrid replacement for their bladed CB and MB clubs. However even with a premium price they proved so popular that in certain parts of the world like Japan you could also get a full set.
Now with the Titleist 718 T-MB irons, they come as a full set for the whole world and definitely sit within the iron category.

Titleist has actually categorised them as distance irons along with 718 AP3 and 718 AP1 because they have a cast, hollow head with an unsupported face to maximise ball speed.

However when you put them down their appearance is pretty blade-like right throughout the set.

The T-MB is a pretty similar size to the 718 AP2 irons that by name should begin with the AP1 and AP3, but are categorised in the Tour category because of their head size, forged construction and supported face.

A better way to view AP2 and T-MB might be to say that they are 'players improvement' irons in their own category, as they offer more forgiveness and higher launch in a slightly larger head than the 718 MB and 718 CB, but still look more compact and like blades when compared to the 718 AP3 and 718 AP1.

The 2 to 7 irons feature a cast 17-4 stainless steel body that has a Japanese Spring Steel L face insert that wraps around the front of the sole to move the join back on to the sole.

In the heel and toe is an average of 93.9g of high density tungsten, up from 80g in the 716 T-MB model, to increase the MOI and give the 718 T-MB its forgiveness.
The bronze PVD finish continues on the sole and is there to illustrate that the tungsten is in there, but it is just in the heel and toe and not right across the back like the finish. I am not sure it adds to the looks when you have the full set in there, but at least it is distinctive.

In the 8 to W heads, the face is also 17-4 steel but going through the set it is hard to notice the difference.
When you put it at address you can't really tell that the blade looking iron in front of you is actually hollow. It sits very well and even with the 4 iron you can't make out any cavity.

The sound and feel is really good and compared to the long irons in the AP2 the T-MB offers a little more launch and possibly a little more forgiveness. The lofts are 1° stronger than 718 AP2 throughout the set to account for the slightly higher launch.

The T-MB heritage is as a hybrid iron as Jordan Speith made famous by hitting his #3 T-MB from the practice range en route to winning the 2017 Open Championship.

At the Titleist launch I even had a go of a similar spec club with his orange Tour AD X-stiff graphite shaft and can see why he prefers that over long irons as you just had a greater sense of forgiveness than AP2 without sacrificing any feel.

What is even more impressive is the short irons, especially the wedge, which look and feel like blade style short irons, but which you know has a hollow head and that makes it feel like you are cheating the system somehow.

The Titleist 718 T-MB is a clever and good fun set for single figure players that would offer some extra forgiveness and ball speed for those who want to play an iron that looks like a blade at address, but who need more margin for error.

However it is particularly pricey and there would have to be a significant performance advantage over one of the other Titleist sets to justify the extra £80/$90 per club investment.
For those that have the means I would expect the majority to do some blending of T-MB with other 718 sets. Like the AP2, the T-MB is now under threat from the new AP3 in the long irons, just because you get the same good feel with even more forgiveness.

Further down the bag and it is a close thing between T-MB and AP2 as I think they overlap a lot and both would provide for an interesting afternoon of testing to see which one to go for or which blend of either would work with the 718 CB or 718 AP3 in a mixed set. As ever in this middle sector of the 718 range, visiting a Titleist fitter would be essential to get the best option.