Mrs. Kubb
6th Grade
October 6, 2011
What will best holds two pieces of
pine together, a screw or a nail?
Hypothesis:
My hypothesis is that a screw will hold two
pieces of pine together better than a
nail.
Materials :
 3,
1½ inch wood screws
 3, 1½ inch nails
 2 pieces of 2 x 4 scrap pine (about the same
length)
 Claw Hammer
 Screwdriver
 3 pound sledge hammer
 Vice
 Ruler
Safety:
1) Wear safety goggles.
 I wore safety goggles to protect my eyes
when I sawed the wood and used the
hammer.
2)Clean work space.
 I made sure that the work space was clean so
that no injuries would occur. Such as stepping
on a nail.
Procedure:
1) Saw 1, 2x4 into 6 equal parts
2) Screw 3 of the 6 cut boards on the 2
inch side of the other 2 x 4
3) Nail the other 3 cut boards on the 2 inch
side of the other 2 x 4
4) Number the pieces 1-3 for the nails and
for the screws
Procedure continued:
5) Put the opposite side of the board into a vice.
Tighten the vice to hold the board steady.
6) Hold the sledge hammer with two hands and let
the head of the hammer drop towards nail 1.
Let the hammer drop 5 times.
7) Using the ruler measure the distance between
nail board 1 and the 2 x 4 block.
8) Repeat steps 6 and 7 for Nails 2 and 3 and for
screws 1-3.
Variables:
Independent variables:
 Nails/screws
Controlled variables:
 pine wood
 3 pound sledge
 number of hits
Data Collection:
Trial
1
2
3
Screw Distance (mm)
0 mm (loosened
enough to wiggly
the board)
2 mm
0 mm (loosened
enough to wiggly
the board)
Nail Distance (mm)
Completely off
(45 mm)
Completely off
(45 mm)
22 mm
I estimated that a 1 ½ in nail and screw was about 3.8 cm in length. Given
the wood width I am saying that a board that fell off went a total distance of
4.5 cm (45 mm).
Data Analysis:
Screw and Nail Test
45
Distance in mm
40
35
30
Trial 1
Trial 2
Trial 3
25
20
15
10
5
0
Screws
Nails
Conclusion:
In conclusion, my hypothesis stated that screws
would hold pine together better than nails. My
hypothesis was correct. According to the data
screws held the boards together because the
largest distance was 2 mm. The nails did not
keep the 2 pieces of wood together, instead the
wood fell off. Possible problems that may have
occurred during the lab were that the amount of
force delivered by the hammer may not of been
the same for each trial. Another problem was
hitting each board on the same spot. Possible
solution for the amount of force would be to set
weights on the overhang part of the board and
see how much weight each would hold.