Description of the issue:

Feedthrough Connectors cannot be made with Seared Bricks from Tinker's Construct.

Side-by-side comparison:

Versions & Modlist

Forge Version 14.23.4.2755
Immersive Engineering Version 0.12-84
Mantle 1.3.2.24
Tinkers' Construct 1.12.2-2.10.1.87
(I doubt the ones below affect this at all and do not believe this is a bug, per se.)
Farseek 2.3.1
Just Enough Items 4.11.0.212
JourneyMap 1.12.2-5.5.2
Streams 0.4.4