Metallurgy had plenty of impact on pre-industrial ships. The main effects were due to:

1. Woodworking technology

2. Metal components used in ships

3. Weapons

1. Woodworking technology

A planked ship can be built with no metal components, and using no metal tools. The timber can be felled by stone axes, the planks produced by splitting with wedges, and the planks and frame fastening by sewing, by wooden pins, or by mortise-and-tenon joints. However, it is quicker and easier to build such a ship using metal tools. Metal axes, especially with hardened steel edges, will greatly ease the felling, and metal tools such as planes, shavers, scrapers etc will greatly ease the finishing of planks. Metal tools will also make the splitting of the felled timber into planks easier, but will make less difference than metal tools in felling and finishing. While the final ship (assuming no metal components) will look very similar, the metal-tool-made ship will be much cheaper (due to lower labour costs). Much cheaper = significant impact.

The difference in labour costs between metal-tool and non-metal-tool planked ships might be large enough to have resulted in the planked ship not being developed before metal tools - the oldest excavated planked ships are Egyptian, c. 2600BC, and post-date metal tools. A variety of ship/boat types are known to have been used, and all had lower labour requirements for being made without metal tools. Such ships/boats included dugout canoes (where much of the woodworking is done by fire, and wooden parts don't need to be finished so as to fit together closely), reed boats/ships, and hides stretched over stick frames. These types of craft continued to be made even after metal tools were available, and some are still used today.

While planked boats can, in principle, be built without metal tools, ships using sawn timber for their frames (in Europe, these become common in late Medieval times) require metal tools. Since sawing allowed more efficient use of timber, and allowed the use of lower-quality timber, much of the impact of sawing was economic.

2. Metal components used in ships

Metal components used in ships included:

Fastenings such as nails, rivets, and bolts. Metal fastenings were used in Ancient Greek and Roman ships, but even when metal fastenings were readily available, sewn construction was often preferred due to the greater flexibility of the structure. As ships became larger, metal fastenings saw more use, and were important in late developments such as very large composite masts. The initial impact on ship design and building was small, but grew larger, until it had a large impact.

Hull sheathing such as lead sheets to protect wooden hulls from worms. Lead sheeting was used in Ancient Roman ships.

Other components such as pulleys, oarlocks, hooks, anchors, hinges, stoves, etc.

3. Weapons

Bronze rams were used in Greek and Roman warships, and had a major impact on the design and use of ships in battle. In many cases, quite literally a major impact on the target ship.

Cannon had major effects on the design of warships. Warships had to be able to resist being hit by cannon, and had to be designed to carry cannon.

References:

D.J. Blackman: "Further Early Evidence of Hull Sheathing", The International Journal of Nautical Archaeology, Vol. 1, No. 1 (1972), pp.117-119.

Vagn Fabritius Buchwald, Iron and Steel in Ancient Times, Det Kongelige Danske Videnskabernes Selskab Historisk-filosofiske Skrifter 29, 2005.

Michael McCarthy, Ships' Fastenings: From Sewn Boat to Steamship, Texas A&M University Press, 2005.

Seán McGrail, Boats of the World: From the Stone Age to Medieval Times, Oxford University Press, 2001.