Jack knife question

[TPK]

I was wondering. Is there any big or main difference between...:

Coke Bottle, Coffin or Swell Center Jacks Is it just different names or To the untrained eye they all look pretty much the same. Maybe I just don't know what the difference is.

[1967redrider]

Borrowing John's picture from today, to me a coffin jack has more to do with the bolsters than the frame shape. Maybe Coke Bottles are usually single blades? I hope this helps.

[ea42]

Borrowing John's picture from today, to me a coffin jack has more to do with the bolsters than the frame shape. Maybe Coke Bottles are usually single blades? I hope this helps.

Yes, a coffin jack's caps or the butt end if there are no caps have to have the shape of the old time coffins. They're usually swell center knives too so you get two for one!

Eric

[Gunsil]

I agree completely on the coffin jacks not being coke bottles, they are coffin jacks. To me a swell center jack has both ends the same with a swell center unlike the coke bottle (also called beaver tail by some), and there are plenty of two blade coke bottles. Usually only the large coke bottles are single blades, there are plenty of 3"-4&1/2" two blade coke bottles, and a very few large ones with two blades.

[Mumbleypeg]

Tom, in my opinion those you mentioned all fall under the category of swell center jack. However the coffin jack and coke bottle are sub- categories. They have swell centers but they also have other distinct characteristics that differentiate them. The coffin jack has unique coffin shaped bolsters The coke bottle is called a coke bottle for obvious reasons.

Here are some examples. I included the push button slider as an example that the coke bottle gets its name from the shape - it's not a jack.

Ken

[Quick Steel]

Excellent examples Ken. To me, a Coke Bottle shape is quite distinctive as you have illustrated.

[TPK]

Thanks everyone! I appreciate all your comments!

At first I thought I was asking another stupid question but as it turns out, it was a legitimate question after all.

Ken I think you nailed it with your example pictures. Together with the other posts and comments, it all makes perfect sense now. A "Coffin" looks like a "Coffin" and the bolsters or shape at the butt of the knife is "A dead giveaway!" so to speak. A "Coke bottle" really looks like a "Coke bottle". And a "Swell Center" is just that, swelled in the center. It's actually easy once you understand & see the differences. Before, they were all one pattern in my mind but now I can see the distinct variations.

My-Conclusion: Listen to the name & the name will explain.

Thanks Folks! Appreciate it! Learned something new again.