There have several posts dealing with that information. However, in a nut shell you will be taps for the Bock #5 and #6, and Jowo #5 & #6 if you plan to use those two most commonly used vendors. Here is a list of the various taps and dies, and their cost, that many of us have purchased:
Triple lead taps and Dies | | | | | | | |
| 1 | 2 | 3 | 6 | 9 | 12 | 24 |
M14-.8 | 178.64 | 137.61 | 104.39 | 80.41 | 69.19 | 5,808.00 | 51.81 |
M14-.8 | | | | | | | |
M13-.8 1pc | 162.40 | 125.10 | 94.90 | 73.10 | 62.90 | 52.80 | 47.10 |
M12-.8 | 159.00 | 121.90 | 91.50 | 68.40 | 563.00 | 48.40 | 43.20 |
M11-.8 | 158.00 | 119.80 | 89.50 | 63.45 | 53.45 | 44.10 | 37.70 |
| | | | | | | |
Triple lead Dies | | | | | | | |
| | | | | | | |
M14-.8 HS 1"OD Die | 184.80 | 138.60 | 103.60 | 78.40 | | 70.00 | |
M14x.8 HS 1 1/2"OD Die | 204.10 | 165.10 | 126.10 | 89.70 | | 80.60 | |
M13-.8 HS 1"OD Die | 184.80 | 138.60 | 103.60 | 78.40 | | 70.00 | |
M12-.8 HS 1"OD Die | 184.80 | 138.60 | 103.60 | 78.40 | | 70.00 | |
M11-.8 HS 1"OD DIe | 184.80 | 138.60 | 103.60 | 78.40 | | 70.00 | |
| | | | | | | |
SIngle lead taps | | | | | | | |
| | | | | | | |
M6.4-.6 1pc | 125.00 | 90.20 | 61.90 | 40.15 | 26.15 | 22.45 | 18.40 |
M7.9-.6 | 126.10 | 91.60 | 62.90 | 41.50 | 31.60 | 23.50 | 18.50 |
M6.5-.5 | 125.00 | 90.20 | 61.90 | 40.15 | 26.15 | 22.45 | 18.40 |
M7.5-.5 | 126.10 | 91.60 | 62.90 | 41.50 | 31.60 | 23.50 | 18.50 |
M8.5-1 | 130.35 | 94.10 | 66.99 | 44.66 | 34.35 | 25.65 | 20.80 |
| | | | | | | |
SIngle lead dies | | | | | | | |
| | | | | | | |
M8.5-1 HS 1"OID DIe | 131.60 | 99.40 | 74.20 | 56.00 | | 50.40 | |
These taps and dies can be very expensive to purchase if you try to purchase them as an individual. However, there are periodically group buys put together to get them at a discounted price. The table above shows what one group buy got them for in 2017.
Having given you the bad news first, let me give you some good news. You can use standard single start metric taps and dies for the body, cap, and sections. One document available in the library show a member using a triple (Nib, feed, and housing) for a Cigar pen kit which has a thread of M10X1.
My recommendation would be to get the single start taps and dies and use them first to see if you really want to make what we term as kit less pens. It will be much cheaper if you decide that these types of pens are not for you.