What method is recommended for ensuring accurate hole dimensions when preparing for riveting?

Reaming after drilling is the recommended method for ensuring accurate hole dimensions when preparing for riveting. This process improves the precision of the hole's diameter and creates a smoother finish. Drilling alone may not provide the level of accuracy needed, as it can leave holes that are slightly oversized or irregular due to various factors like drill bit wear or material variations.

Reaming serves to enlarge the hole to a precise dimension while also helping to align the hole perfectly for the rivet, ensuring that it fits snugly without unnecessary play. A reamer is specifically designed to produce a high-precision hole, which is crucial in structural applications where the strength of the joint can be affected by the accuracy of the fastener dimensions.

While using a template might assist in position accuracy and drilling holes in a straightforward way, it does not enhance hole dimension precision after drilling, making it less effective than reaming. Adjustable drills may offer some versatility but do not ensure the most accurate hole size in all cases, as their settings may not always be perfectly calibrated. Therefore, reaming is the preferred method to achieve the necessary precision for riveting holes.