Can someone help identify these lug bolts?

[junkyarddog]

I am having trouble identifying these lug bolts.

The first picture shows a smooth head with hex inside. there is a line around the bottom of the head just above where the taper starts. The threads are 3/8-20. The
bottom extends about a quarter inch below the threads.

The second picture shows a hew head 9/16. The threads are 3/8-24.

Any and all help would be appreciated. Eileenlug nut a.JPGhexlugnut1.JPG

[DuoGlide62]

I think the first picture shows '38 to '41 H-D . I'm not an expert or anything but I read it on Matt Olsen's site. Looks the same to me.

http://oldbikesinsd.blogspot.com/2011/08/39-el-pictures.html

[Chris Haynes]

I think the first picture shows '38 to '41 H-D . I'm not an expert or anything but I read it on Matt Olsen's site. Looks the same to me.
http://oldbikesinsd.blogspot.com/201...-pictures.html

Actually it is 1936 thru 1939. Used first on the 1936 61 and on all models thru 1939 with the stepped hub.

[exeric]

I believe the bolt in the 2nd picture is Indian. It looks like the brake drum bolts in my '40 Chief.

[bernhardt]

Chris,

Wouldn't the '36 lug bolts be drilled also? And thereafter un-drilled, but with the line near the taper?

[Chris Haynes]

I have four different examples of those bolts. Holes, no holes, groove at top, and groove at the bottom. When were they used? Can't tell from factory photos.