So how do you use blanks with bolt holes in them? Some people hate them, and some people love them. I am in the "love them" camp.
Here are some sample blanks with bolt hols in there.
Ever wondered why there are bolt holes in the seats before? Take a look at this red seat bottom from Sportsman's Park. You can see the four corner bolt holes in the seat. Those holes were used to bolt the seat bottle to the frame of the stadium seat. Look closer at the small line of spacers between each seat slat. There are two lines of spacers where a steel rod runs the length of the seat. This rod holds all the slats together.
Looking at the bottom of this Boston Garden seat bottom you can see that the wood is attached to the stadium frame a bit differently. This type of chair has 1/2" holes shallow drilled into each slat. You can see this type of hole in the Ebbets Field blank in the first image. You can seen the back of the closest seat slat where there is a small hole; this is the metal rod that holds the metal seat arm to the wood slats.
Putting the use of the bolt hole in perspective, I make use of the bolt and support holes as features on my pens. Take a look at these two pen examples where the bolt holes were made a feature. This pen was made from Yankee Stadium seat wooden slats.
Here is another example of a pen made by Ron Both. The wood is from a Chicago Stadium seat. You can see the rust patina that has sent into the wood from the rusted metal rod of the seat.
I recently did a Yankee Stadium pen grouping of four pens.... all the same Jr Retro Rhodium kit from Craft Supplies USA. Pen One was cleanly turned and no defects of blemishes. Pen Two was turned off-center so that there was paint left on the finished pen. Pen Three was cleanly turned with a bolt hole similar to this one. Pen Four was turned off-center with a bolt hole.
Pen One sold for $189
Pen Two sold for $279
Pen three sold for $249
Pen Four sold for $359
This is Pen One.
This is a pic of Pen Four.
And here is the bolt hole of Pen Four.