This was of solid construction, though even they had lightening holes.

I am using a circle cutter to rough cut the lightening holes.

With the two separated I used a 25mm hole punch to open up the three lightening holes in each piece.

A row of similar circles in a plate might suggest lightening holes.

Make the control surfaces from 9.5mm sheet balsa, cutting out the lightening holes as you go.

The main beams of the car's frame had large lightening holes, and the wheel wells under the body were used as stressed members.

Port wing showing aileron lightening holes and torque tube drive system.

From late 1937, selected riders were given the new plunger type rear suspension but without all the lightening holes.

Changes included reducing the number of full wing ribs and cutting lightening holes in the main spar.

May 6th Filled the gap between the cores and the spar and most of the lightening hole gaps.

March 1st Cut the lightening hole cores for all of the starboard wing blocks and epoxied them in place.

As this coincided with the foam between two lightening holes it was stopping the two surfaces coming together.

Many fuel tanks' baffles (particularly in aircraft and racecars) contain lightening holes.

Except for a few small lightening holes, this disk wheel is consistently one wall thickness thick, all around the disk.

Prepared 8 aft rib blanks for bending by cutting to size and routing out the lightening holes.

The wing lighting duct hole is bored 10cm up from the spar and comes out into the first lightening hole in the second block.

Internal bracing wires were not used in the wings as it was built up from plywood ribs with large lightening holes and stringers.

Owing to the increasing number of dangerous failures, the practice of drilling lightening holes was forbidden by the race scrutineers.

It features Friend(R) removal hooks and lightening holes for clipping to a Karabiner.

While the epoxy was drying I got my hobby blowtorch out, heated a rod and made the air vent holes in the lightening holes.

One final inspection, reinsertion of the lightening hole cores for storage, and the fin was tucked away safely until it is ready for baking.

Lightening holes are holes in structural components of machines and buildings used by a variety of engineering disciplines to make structures lighter.

The Stoner 63A bipod is extensively perforated with lightening holes and can be locked in either the stowed or deployed positions.

The BFB comprises a single disc, with teardrop-shaped indentations to give rigidity, and lightening holes to reduce weight.