5.24 DRILLING, TAPS AND DIES (continued)
SOME NOTES ON TAPS
A "tap" is a tool used for cutting internal threads into an existing hole. Taps come in several styles. The most common
hardware store variety is a four-flute tap. The flute is the groove along the length of the tool. When using a
tap on metal, some lubricant should be used. Common motor oil is OK for steel while kerosene works well on
aluminum. Plastic needs no lubricant.
Starting the tap straight in the hole is very important. Most broken taps are due to hole misalignment. The best way to get the tap
started straight is to use a drill press. Clamp the work in a vise and with the tap in the chuck, turn the chuck by hand.
When tapping a deep hole it is best to back the tap out about one turn to every two turns in. In this way the resulting chips are
allowed to clear from the flutes. Do not allow the tap to get stuck by turning too many times without clearing; another cause of
broken taps.
An 8-32 tap means that the screw size is #8 and it has 32 threads per inch (pitch). Fractional sizes like ¼-20 mean the screw is 1/4"
and has 20 threads per inch.
5.25 DIMENSIONS
Dimensions in newer kits are depicted in English
fractional form with a 1/32 inch accuracy where
possible. Other dimensions, not lending
themselves readily to a 1/32 of an inch
conversion, are depicted in decimal form with
a three decimal place accuracy. We realize
that most tape measures do not have three
decimal place accuracy, and so have provided
a conversion table to facilitate conversion
between fractions and decimals.
Holes as provided in the kit will be called
out as decimals, but after drilling, they will
be referred to by the drill bit size used to
drill them. Example: "Drill #40 the .094 [2.4 mm]
holes in the dingus. Dimple the #40 holes."
In many cases, use of the nearest
fractional measurement to a decimal place
dimension is sufficient, but use your best
judgement, especially in areas that may
require high precision to fit correctly.
All dimensions are also depicted in metric
measurements.
1/32
1/16
3/32
1/8
5/32
3/16
7/32
1/4
9/32
5/16
11/32
3/8
13/32
7/16
15/32
1/2
FIGURE 1: FRACTION TO DECIMAL CONVERSION
17/32
9/16
19/32
5/8
21/32
11/16
23/32
3/4
25/32
13/16
27/32
7/8
29/32
15/16
31/32
1 1.000
0.032
0.063
0.094
0.125
0.156
0.188
0.219
0.250
0.281
0.313
0.344
0.375
0.406
0.438
0.469
0.500
0.531
0.563
0.594
0.625
0.656
0.688
0.719
0.750
0.781
0.813
0.844
0.875
0.906
0.938
0.969
1.000
FIGURE 2: NUTPLATE
IDENTIFICATION
(SEE VAN'S CATALOG FOR
COMPLETE DESCRIPTIONS
SCALE 1:1
K1000-3
K1000-4
K1000-5
K1000-6
K1000-06
K1000-08D
K1100-06
K1100-08
MK1000-4
MS21051-L3
MS21051-L06
MS21051-L08
MS21053-L08
K1000-08
K1100-08D
DIMPLED RIVET HOLES
DIMPLED RIVET HOLES
5.26 HARDWARE REFERENCE
PAGE
REVISION:
DATE:
VAN'S AIRCRAFT, INC.
PAGE
REVISION:
DATE:
09/24/13
05-30 RV-ALL
1